BR122024006265A2 - IMAGE DECODING APPARATUS, IMAGE CODING APPARATUS AND APPARATUS FOR TRANSMITTING DATA FOR IMAGE INFORMATION - Google Patents

Abstract

A picture decoding method performed by a decoding device according to this document comprising the steps of: acquiring a signal data hiding enabled flag; acquiring a transform omission residual coding (TSRC) enabled flag based on the signal data hiding enabled flag; acquiring residual information for a current block based on the TSRC enabled flag; deriving a residual sample of the current block based on the residual information; and generating a reconstructed picture based on the residual sample, wherein the signal data hiding enabled flag is a flag indicating whether signal data hiding is enabled, the TSRC enabled flag is a flag indicating whether TSRC is enabled, and the TSRC enabled flag is acquired based on the signal data hiding enabled flag having a value of zero.

Description

FUNDAMENTALS OF REVELATION Field of revelation

[001] The present disclosure relates to a picture coding technology, and more particularly to a picture decoding method and an apparatus thereof, that encodes flag information representing whether TSRC is enabled into residual coding data of a current block in a picture coding system.

Related technique

[002] Recently, the demand for high-resolution and high-quality images such as High Definition (HD) images and Ultra High Definition (UHD) images has increased in various fields. Since image data has high resolution and high quality, the amount of information or bits to be transmitted increases relative to legacy image data. Therefore, when image data is transmitted using a medium such as a conventional wired/wireless broadband line or image data is stored using an existing storage medium, the transmission costs and storage costs thereof are increased.

[003] Correspondingly, there is a need for a highly efficient image compression technique to effectively transmit, store and reproduce high-resolution, high-quality image information.

SUMMARY

[004] The present disclosure provides a method and apparatus for improving image coding efficiency.

[005] The present disclosure also provides a method and apparatus for improving residual coding efficiency.

[006] According to an embodiment of the present disclosure, there is provided a picture decoding method performed by a decoding apparatus. The method includes: obtaining a signal data hiding enabled flag; obtaining a transform skip residual coding (TSRC) enabled flag based on the signal data hiding enabled flag; obtaining residual information for a current block based on the TSRC enabled flag; deriving a residual sample of the current block based on the residual information; and generating a reconstructed picture based on the residual sample, wherein the signal data hiding enabled flag is a flag for whether a signal data hiding is enabled, wherein the TSRC enabled flag is a flag for whether a TSRC is enabled, and wherein the TSRC enabled flag is obtained based on the signal data hiding enabled flag having a value of 0.

[007] According to another embodiment of the present disclosure, a decoding apparatus is provided that performs picture decoding. The decoding apparatus includes: an entropy decoder configured to obtain a signal data hiding enabled flag, obtain a transform skip residual coding (TSRC) enabled flag based on the signal data hiding enabled flag, obtain residual information for a current block based on the TSRC enabled flag; a residual processor configured to derive a residual sample of the current block based on the residual information; and an adder configured to generate a reconstructed picture based on the residual sample, wherein the signal data hiding enabled flag is a flag for whether signal data hiding is enabled, wherein the TSRC enabled flag is a flag for whether TSRC is enabled, and wherein the TSRC enabled flag is obtained based on the signal data hiding enabled flag having a value of 0.

[008] According to yet another embodiment of the present disclosure, there is provided a method of encoding video performed by an encoding apparatus. The method includes: encoding a signal data concealment enabled flag for whether signal data concealment is enabled; encoding a transform skip residual coding (TSRC) enabled flag for whether TSRC is enabled based on the signal data concealment enabled flag; encoding residual information for a current block based on the TSRC enabled flag; and generating a bit stream including the signal data concealment enabled flag, the TSRC enabled flag, and the residual information, wherein the TSRC enabled flag is encoded based on the signal data concealment enabled flag having a value of 0.

[009] According to yet another embodiment of the present disclosure, a video encoding apparatus is provided. The encoding apparatus includes an entropy encoder configured to encode a signal data hiding enabled flag for whether signal data hiding is enabled, encode a transform skip residual coding (TSRC) enabled flag for whether TSRC is enabled based on the signal data hiding enabled flag, encode residual information for a current block based on the TSRC enabled flag, generate a bit stream including the signal data hiding enabled flag, the TSRC enabled flag, and the residual information, wherein the TSRC enabled flag is encoded based on the signal data hiding enabled flag having a value of 0.

[010] According to yet another embodiment of the present disclosure, there is provided a non-transitory computer-readable storage medium that stores a bit stream including image information that induces performing an image decoding method. On the non-transitory computer-readable storage medium, the image decoding method includes: obtaining a signal data hiding enabled flag; obtaining a transform skip residual coding (TSRC) enabled flag based on the signal data hiding enabled flag; obtaining residual information for a current block based on the TSRC enabled flag; deriving a residual sample of the current block based on the residual information; and generating a reconstructed figuration based on the residual sample, wherein the signal data hiding enabled flag is a flag for whether signal data hiding is enabled, wherein the TSRC enabled flag is a flag for whether TSRC is enabled, and wherein the TSRC enabled flag is obtained based on the signal data hiding enabled flag having a value of 0.

[011] According to the present disclosure, residual coding efficiency can be enhanced.

[012] According to the present disclosure, the TSRC-enabled flag can be signaled when signal data hiding is not enabled by adjusting the signaling relationship between the signal data hiding-enabled flag and the TSRC-enabled flag, whereby, when the RRC syntax is coded for the transform omission block because TSRC is not enabled, signal data hiding is not used to improve the coding efficiency, and the overall residual coding efficiency can be improved by reducing the amount of bits being coded.

[013] According to the present disclosure, the signaling relationship between a dependent quantization-enabled flag and a TSRC-enabled flag is established, and if dependent quantization is not enabled, the TSRC-enabled flag can be signaled, and thereby, if TSRC is not enabled and an RRC syntax is coded for a transform omission block, dependent quantization should not be used, so that the coding efficiency is improved, and the overall residual coding efficiency can be improved by reducing the amount of bits being coded.

[014] According to the present disclosure, the signaling relationship is established between a transform omission enabled flag and the TSRC enabled flag, and if transform omission is enabled, the TSRC enabled flag can be signaled, and thereby, the overall residual coding efficiency can be improved by reducing the amount of bits being coded.

BRIEF DESCRIPTION OF THE DRAWINGS

[015] Figure 1 briefly illustrates an example of a video/image encoding device to which embodiments of the present disclosure are applicable.

[016] Figure 2 is a schematic diagram illustrating a configuration of a video/image encoding apparatus to which embodiments of the present disclosure may be applied.

[017] Figure 3 is a schematic diagram illustrating a configuration of a video/image decoding apparatus to which embodiments of the present disclosure may be applied.

[018] Figure 4 shows, by way of example, a context-adaptive binary arithmetic coding (CABAC) for encoding a syntax element.

[019] Figure 5 is a diagram that shows, by way of example, transform coefficients in a 4x4 block.

[020] Figure 6 illustrates, by way of example, scalar quantizers being used in dependent quantization.

[021] Figure 7 illustrates, by way of example, state transition and quantizer selection for dependent quantization.

[022] Figure 8 briefly illustrates an image encoding method performed by an encoding apparatus in accordance with the present disclosure.

[023] Figure 9 briefly illustrates a coding apparatus for performing an image coding method in accordance with the present disclosure.

[024] Figure 10 briefly illustrates an image decoding method performed by a decoding apparatus in accordance with the present disclosure.

[025] Figure 11 briefly illustrates a decoding apparatus for performing an image decoding method in accordance with the present disclosure.

[026] Figure 12 illustrates a structural diagram of a content streaming system to which the present disclosure is applied.

DESCRIPTION OF EXEMPLIFYING MODALITIES

[027] The present disclosure may be modified in various ways, and specific embodiments thereof will be described and illustrated in the drawings. However, the embodiments are not intended to limit the disclosure. The terms used in the following description are used to merely describe specific embodiments, but are not intended to limit the disclosure. An expression of a singular number includes an expression of the number in the plural, provided that it is clearly read differently. The terms “include” and “have” are intended to indicate that features, numbers, steps, operations, elements, components or combinations thereof used in the following description exist, and therefore it is to be understood that the possibility of the existence or addition of one or more different features, numbers, steps, operations, elements, components or combinations thereof is not excluded.

[028] However, elements in the drawings described in the disclosure are independently drawn for the purpose of convenience for explaining different specific functions, and does not mean that the elements are embodied by independent hardware or independent software. For example, two or more elements may be combined to form a single element or an element may be partitioned into multiple elements. The embodiments whose elements are combined and/or partitioned belong to the disclosure without departing from the concept of the disclosure.

[029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, similar reference numbers are used to indicate similar elements throughout the drawings, and the same descriptions in the similar elements will be omitted.

[030] Figure 1 briefly illustrates an example of a video/image encoding device to which embodiments of the present disclosure are applicable.

[031] Referring to Figure 1, a video/image encoding system may include a first device (source device) and a second device (receiving device). The source device may deliver encoded video/image information or data in the form of a file or stream to the receiving device via a digital storage medium or network.

[032] The source device may include a video source, an encoding apparatus, and a transmitter. The receiving device may include a receiver, a decoding apparatus, and a renderer. The encoding apparatus may be referred to as a video/image encoding apparatus, and the decoding apparatus may be referred to as a video/image decoding apparatus. The transmitter may be included in the encoding apparatus. The receiver may be included in the decoding apparatus. The renderer may include a display, and the display may be configured as a separate device or an external component.

[033] The video source may acquire video/image through a process of capturing, synthesizing, or generating the video/image. The video source may include a video/image capture device and/or a video/image generation device. The video/image capture device may include, for example, one or more cameras, video/image files including previously captured videos/images, and the like. The video/image generation device may include, for example, computers, tablets, and smartphones, and may generate (electronically) video/images. For example, a virtual video/image may be generated through a computer, or the like. In this case, the video/image capture process may be replaced by a process of generating related data.

[034] The encoding apparatus may encode input image/picture. The encoding apparatus may perform a series of procedures such as prediction, transformation, and quantization for compression and coding efficiency. The encoded data (encoded video/picture information) may be output in the form of a bit stream.

[035] The transmitter may transmit the output encoded image/picture information or data in the form of a bit stream to the receiver of the receiving device via a digital storage medium or a network in the form of a file or stream. The digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD and the like. The transmitter may include an element for generating a media file via a predetermined file format and may include an element for transmission via a broadcasting/communication network. The receiver may receive/extract the bit stream and transmit the received bit stream to the decoding apparatus.

[036] The decoding apparatus may decode the video/image by performing a series of procedures such as dequantization, inverse transform, and prediction corresponding to the operation of the encoding apparatus.

[037] The renderer can render the decoded video/image. The rendered video/image can be displayed through the screen.

[038] The present disclosure relates to video/image coding. For example, the methods/embodiments disclosed in the present disclosure may be applied to a method disclosed in the Versatile Video Coding (VVC), EVC (Essential Video Coding) standard, AOMedia Video 1 (AV1) standard, 2nd Generation Video and Audio Coding Standard (AVS2), or the next generation video/image coding standard (e.g. H.267 or H.268, etc.).

[039] The present disclosure presents various embodiments of video/image encoding, and the embodiments may be performed in combination with each other except where otherwise noted.

[040] In the present disclosure, video may refer to a series of images over time. In general, a picture refers to a unit that represents an image in a specific time zone, and a subslice/slice/tile is a unit that constitutes part of a picture in coding. A subslice/slice/tile may include one or more coding tree units (CTUs). A picture may consist of one or more subslices/slices/tiles. A picture may consist of one or more tile groups. A tile group may include one or more tiles. A brick may represent a rectangular region of CTU rows in a tile in a picture. A tile may be partitioned into multiple bricks, each of which consists of one or more CTU rows within the tile. A tile that is not partitioned into multiple bricks may also be referred to as a brick. A brick scan is a specific sequential ordering of CTUs that partition a pattern in which CTUs are ordered consecutively in a CTU raster scan in a brick, bricks within a tile are ordered consecutively in a raster scan of the tile's bricks, and tiles in a pattern are ordered consecutively in a raster scan of the pattern's tiles. Additionally, a sub-pattern may represent a rectangular region of one or more slices in a pattern. That is, a sub-pattern contains one or more slices that collectively span a rectangular region of a pattern. A tile is a rectangular region of CTUs within a particular tile column and a particular tile row in a pattern. A tile column is a rectangular region of CTUs having a height equal to the pattern's height and a width specified by the syntax elements in the pattern parameter set. A tile row is a rectangular region of CTUs having a height specified by the syntax elements in the pattern parameter set and a width equal to the pattern's width. A tile scan is a specific ordering of CTUs that partition a pattern in which the CTUs are ordered consecutively in a CTU raster scan in a tile while the tiles in a pattern are ordered consecutively in a raster scan of the pattern's tiles. A slice includes an integer number of tiles of a pattern that can be uniquely contained in a single NAL unit. A slice may consist of a number of complete tiles or only a consecutive sequence of complete tiles of a tile. Tile groups and slices may be used interchangeably in the present disclosure. For example, in the present disclosure, a tile group/tile group header may be referred to as a slice/slice header.

[041] A pixel or a pel may mean a smallest unit that constitutes a picture (or image). Similarly, ‘sample’ may be used as a term corresponding to a pixel. A sample may, in general, represent a pixel or a pixel value, and may represent only a pixel/pixel value of a luma component or only a pixel/pixel value of a chroma component.

[042] A unit may represent a basic image processing unit. The unit may include at least one of a specific region of the image and information related to the region. A unit may include one luma block and two chroma blocks (e.g. cb, cr). The unit may be used interchangeably with terms such as block or area in some cases. In a general case, an MxN block may include samples (or sample arrays) or a set (or array) of transform coefficients of M columns and N rows.

[043] In this description, “A or B” may mean “A only”, “B only” or “both A and B”. In other words, in this specification, “A or B” may be interpreted as “A and/or B”. For example, “A, B or C” in this document means “A only”, “B only”, “C only”, or “any and all combinations of A, B and C”.

[044] A slash (/) or a comma (comma) used in this description may mean “and/or”. For example, “A/B” may mean “A and/or B”. Correspondingly, “A/B” may mean “A only”, “B only”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”.

[045] In the present description, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. Furthermore, in the present description, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as equal to “at least one of A and B”.

[046] Furthermore, in the present description, “at least one of A, B, and C” means “A only,” “B only,” “C only,” or “any combination of A, B, and C.” Likewise, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C.”

[047] Furthermore, parentheses used in this description may mean “for example”. Specifically, when “prediction (intraprediction)” is indicated, “intraprediction” may be proposed as an example of “prediction”. In other words, “prediction” in this description is not limited to “intraprediction”, and “intraprediction” may be proposed as an example of “prediction”. Likewise, even when “prediction (i.e., intraprediction)” is indicated, “intraprediction” may be proposed as an example of “prediction”.

[048] In the present description, technical features that are individually described in a drawing can be individually implemented or can be implemented at the same time.

[049] The following drawings have been created to explain a specific example of the present description. Since the names of specific devices described in the drawings or the names of specific signals/messages/fields are presented by way of example, the technical features of the present description are not limited to the specific names used in the following drawings.

[050] Figure 2 is a schematic diagram illustrating a configuration of a video/image encoding apparatus to which embodiments of the present disclosure may be applied. Hereinafter, the video encoding apparatus may include an image encoding apparatus.

[051] Referring to Figure 2, the encoding apparatus 200 includes an image partitioner 210, a predictor 220, a residual processor 230, and an entropy encoder 240, an adder 250, a filter 260, and a memory 270. The predictor 220 may include an interpredictor 221 and an intrapredictor 222. The residual processor 230 may include a transformer 232, a quantizer 233, a dequantizer 234, and an inverse transformer 235. The residual processor 230 may further include a subtractor 231. The adder 250 may be referred to as a reconstructor or a reconstructed block generator. The image partitioner 210, the predictor 220, the residual processor 230, the entropy encoder 240, the adder 250, and the filter 260 may be configured by at least one hardware component (e.g., an encoder chipset or processor) according to one embodiment. In addition, the memory 270 may include a decoded picture buffer (DPB) or may be configured by a digital storage medium. The hardware component may further include the memory 270 as an internal/external component.

[052] The image partitioner 210 may partition an input image (or a picture or a frame) input to the encoding apparatus 200 into one or more processors. For example, the processor may be referred to as a coding unit (CU). In this case, the coding unit may be recursively partitioned according to a quaternary tree binary tree tertiary tree (QTBTTT) structure from a coding tree unit (CTU) or a largest coding unit (LCU). For example, a coding unit may be partitioned into a plurality of coding units of a deeper depth based on a quaternary tree structure, binary tree structure, and/or a tertiary structure. In this case, for example, the quaternary tree structure may be applied first and the binary tree structure and/or tertiary structure may be applied later. Alternatively, the binary tree structure may be applied first. The coding procedure according to the present disclosure may be performed based on the final coding unit that is no longer partitioned. In this case, the largest coding unit may be used as the final coding unit based on the coding efficiency according to image characteristics, or, if necessary, the coding unit may be recursively partitioned into deeper depth coding units and a coding unit having an optimal size may be used as the final coding unit. In the present document, the coding procedure may include a prediction, transform, and reconstruction procedure, which will be described later. As another example, the processor may further include a prediction unit (PU) or a transform unit (TU). In this case, the prediction unit and the transform unit may be divided or partitioned from the aforementioned final coding unit. The prediction unit may be a sample prediction unit, and the transform unit may be a unit for deriving a transform coefficient and/or a unit for deriving a residual signal from the transform coefficient.

[053] The unit may be used interchangeably with terms such as block or area in some cases. In a general case, a block M*N may represent a set of samples or transform coefficients composed of M columns and N rows. A sample may generally represent a pixel or a pixel value, it may represent only a pixel/pixel value of a luma component, or it may represent only a pixel/pixel value of a chroma component. A sample may be used as a term corresponding to a figuration (or image) for a pixel or a pel.

[054] In the encoding apparatus 200, a prediction signal (predicted block, prediction sample array) output from the interpredictor 221 or the intrapredictor 222 is subtracted from an input image signal (original block, original sample array) to generate a residual signal block (residual sample array), and the generated residual signal is transmitted to the transformer 232. In this case, as shown, a unit for subtracting a prediction signal (predicted block, prediction sample array) from the input image signal (original block, original block array) in the encoder 200 may be referred to as a subtractor 231. The predictor may perform a prediction on a block to be processed (hereinafter, referred to as a current block) and generate a predicted block including prediction samples for the current block. The predictor may determine whether an intra-prediction or an inter-prediction is applied on a current block or CU basis. As described further in the description of each prediction mode, the predictor may generate various prediction-related information, such as prediction mode information, and transmit the generated information to the entropy encoder 240. The prediction information may be encoded in the entropy encoder 240 and output in the form of a bit stream.

[055] The intrapredictor 222 may predict the current block by referring to samples in the current picture. The referred samples may be located in the vicinity of the current block or may be located apart according to the prediction mode. In intraprediction, the prediction modes may include a plurality of non-directional modes and a plurality of directional modes. The non-directional mode may include, for example, a DC mode and a planar mode. The directional mode may include, for example, 33 directional prediction modes or 65 directional prediction modes according to the degree of detail of the prediction direction. However, this is merely an example, more or less directional prediction modes may be used depending on a setting. The intrapredictor 222 may determine the prediction mode applied to the current block using a prediction mode applied to a neighboring block.

[056] The interpredictor 221 may derive a predicted block for the current block based on a reference block (reference sample array) specified by a motion vector in a reference picture. Herein, in order to reduce the amount of motion information transmitted in the interprediction mode, the motion information may be predicted in units of blocks, subblocks, or samples based on the correlation of motion information between the neighboring block and the current block. The motion information may include a motion vector and a reference picture index. The motion information may further include interprediction direction information (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of interprediction, the neighboring block may include a spatial neighboring block present in the current picture and a temporal neighboring block present in the reference picture. The reference picture including the reference block and the reference picture including the temporal neighboring block may be the same or different. The temporal neighboring block may be referred to as a co-located reference block, a co-located CU (colCU), and the like, and the reference picture including the temporal neighboring block may be referred to as a co-located picture (colPic). For example, the interpredictor 221 may configure a candidate list of motion information based on neighboring blocks and generate information indicating which candidate is used to derive a motion vector and/or a reference picture index of the current block. Interprediction may be performed based on various prediction modes. For example, in the case of an omission mode and a merging mode, the interpredictor 221 may use motion information of the neighboring block as motion information of the current block. In the omission mode, unlike the merging mode, the residual signal may not be transmitted. In the case of motion vector prediction (MVP) mode, the motion vector of the neighboring block can be used as a predictor motion vector and the motion vector of the current block can be indicated by flagging a motion vector difference.

[057] The predictor 220 may generate a prediction signal based on various prediction methods described below. For example, the predictor may not only apply an intra-prediction or an inter-prediction to predict a block, but may also simultaneously apply both intra-prediction and inter-prediction. This may be referred to as combined inter- and intra-prediction (CIIP). Furthermore, the predictor may rely on an intra-block copy (IBC) prediction mode or a pallet mode for predicting a block. The IBC prediction mode or the pallet mode may be used for image/video coding of content or the like, e.g., screen content coding (SCC). The IBC basically performs a prediction on the current picture, but may be similarly performed for inter-prediction characterized in that a reference block is derived on the current picture. That is, the IBC may use at least one of the inter-prediction techniques described in the present disclosure. Pallet mode can be considered as an example of intracoding or intraprediction. When pallet mode is applied, a sample value within a figuration can be flagged based on information about the pallet table and the pallet index.

[058] The prediction signal generated by the predictor (including interpredictor 221 and/or intrapredictor 222) may be used to generate a reconstructed signal or generate a residual signal. Transformer 232 may generate transform coefficients by applying a transform technique to the residual signal. For example, the transform technique may include at least one of a discrete cosine transform (DCT), a discrete sine transform (DST), a karhunen-loève transform (KLT), a graph-based transform (GBT), or a conditionally nonlinear transform (CNT). In this document, GBT means a transform of a graph when the relationship information between pixels is represented by the graph. CNT refers to a transform generated based on a prediction signal generated using all previously reconstructed pixels. Furthermore, the transform process can be applied to square pixel blocks having the same size or it can be applied to blocks having a variable size rather than square.

[059] The quantizer 233 may quantize the transform coefficients and transmit them to the entropy encoder 240, and the entropy encoder 240 may encode the quantized signal (information about the quantized transform coefficients) and output a bit stream. The information about the quantized transform coefficients may be referred to as residual information. The quantizer 233 may rearrange the block-type quantized transform coefficients into a one-dimensional vector form based on a coefficient scan order, and generate information about the quantized transform coefficients based on the quantized transform coefficients in the one-dimensional vector form. The information on transform coefficients may be generated. The entropy encoder 240 may perform various coding methods, such as exponential Golomb, context adaptive variable length coding (CAVLC), context adaptive binary arithmetic coding (CABAC), and the like. The entropy encoder 240 may encode information required for video/image reconstruction other than the quantized transform coefficients (e.g., syntax element values, etc.) together or separately. The encoded information (e.g., encoded video/image information) may be transmitted or stored in NALs (network abstraction layer) units in the form of a bit stream. The video/image information may further include information on various parameter sets such as an adaptation parameter set (APS), a figuration parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). Furthermore, the video/image information may further include general constraint information. In the present disclosure, information and/or syntax elements transmitted/signaled from the encoding apparatus to the decoding apparatus may be included in video/image information. The video/image information may be encoded by the encoding procedure described above and included in the bit stream. The bit stream may be transmitted over a network or may be stored on a digital storage medium. The network may include a broadcasting network and/or a communication network, and the digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, and the like. A transmitter (not shown) that transmits a signal output from the entropy encoder 240 and/or a storage unit (not shown) that stores the signal may be included as an internal/external element of the encoding apparatus 200, and alternatively, the transmitter may be included in the entropy encoder 240.

[060] The quantized transform coefficients output from quantizer 233 may be used to generate a prediction signal. For example, the residual signal (residual block or residual samples) may be reconstructed by applying dequantization and inverse transform to the quantized transform coefficients via dequantizer 234 and inverse transform 235. Adder 250 adds the reconstructed residual signal to the prediction signal output from interpredictor 221 or intrapredictor 222 to generate a reconstructed signal (reconstructed figuration, reconstructed block, reconstructed sample array). If there is no residual for the block to be processed, such as a case where skip mode is applied, the predicted block may be used as the reconstructed block. Adder 250 may be referred to as a reconstructor or a reconstructed block generator. The generated reconstructed signal can be used for intraprediction of a next block to be processed in the current figuration and can be used for interprediction of a next figuration through filtering as described below.

[061] However, luma mapping with chroma scaling (LMCS) can be applied during coding and/or figuration reconstruction.

[062] Filter 260 may improve subjective/objective image quality by applying filtering to the reconstructed signal. For example, filter 260 may generate a modified reconstructed image by applying various filtering methods to the reconstructed image and store the modified reconstructed image in memory 270, specifically, a DPB of memory 270. The various filtering methods may include, for example, deblocking filtering, an adaptive sample shift, an adaptive loop filter, a bilateral filter, and the like. Filter 260 may generate various filtering-related information and transmit the generated information to entropy encoder 240 as described further in the description of each filtering method. The filtering-related information may be encoded by entropy encoder 240 and output as a bit stream.

[063] The modified reconstructed picture transmitted to the memory 270 can be used as the reference picture in the interpredictor 221. When the interprediction is applied through the encoding apparatus, prediction mismatch between the encoding apparatus 200 and the decoding apparatus 300 can be avoided and the encoding efficiency can be improved.

[064] The DPB of the DPB memory 270 may store the modified reconstructed picture for use as a reference picture in the interpredictor 221. The memory 270 may store the motion information of the block from which the motion information in the current picture is derived (or encoded) and/or the motion information of the blocks in the picture that have already been reconstructed. The stored motion information may be transmitted to the interpredictor 221 and used as the spatial neighbor block motion information or the temporal neighbor block motion information. The memory 270 may store reconstructed samples of reconstructed blocks in the current picture and may transfer the reconstructed samples to the intrapredictor 222.

[065] Figure 3 is a schematic diagram illustrating a configuration of a video/image decoding apparatus to which embodiments of the present disclosure may be applied.

[066] Referring to Figure 3 , decoding apparatus 300 may include an entropy decoder 310, a residual processor 320, a predictor 330, an adder 340, a filter 350, a memory 360. Predictor 330 may include an interpredictor 331 and an intrapredictor 332. Residual processor 320 may include a dequantizer 321 and an inverse transformer 322. Entropy decoder 310, residual processor 320, predictor 330, adder 340, and filter 350 may be configured by a hardware component (e.g., a decoder chipset or a processor) according to one embodiment. Additionally, memory 360 may include a decoded picture buffer (DPB) or may be configured by a digital storage medium. The hardware component may further include memory 360 as an internal/external component.

[067] When a bit stream including video/image information is input, the decoding apparatus 300 may reconstruct an image corresponding to a process in which the video/image information is processed in the encoding apparatus of Figure 2. For example, the decoding apparatus 300 may derive units/blocks based on the block partition related information obtained from the bit stream. The decoding apparatus 300 may perform decoding using a processor applied in the encoding apparatus. Thus, the decoding processor may be a coding unit, for example, and the coding unit may be partitioned according to a quaternary tree structure, binary tree structure, and/or tertiary tree structure from the coding tree unit or the largest coding unit. One or more transform units may be derived from the coding unit. The reconstructed image signal decoded and output through the decoding apparatus 300 may be reproduced through a reproduction apparatus.

[068] The decoding apparatus 300 may receive a signal output from the encoding apparatus of Figure 2 in the form of a bit stream, and the received signal may be decoded by the entropy decoder 310. For example, the entropy decoder 310 may analyze the bit stream to derive information (e.g., video/image information) necessary for image reconstruction (or picture reconstruction). The video/image information may further include information in various parameter sets such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video/image information may further include general constraint information. The decoding apparatus may further decode a picture based on the information in the parameter set and/or the general constraint information. The signaled/received information and/or syntax elements described later in the present disclosure that can be decoded can decode the decoding procedure and obtained from the bit stream. For example, the entropy decoder 310 decodes the information in the bit stream based on a coding method such as Golomb exponential coding, CAVLC, or CABAC, and outputs syntax elements required for image reconstruction and quantized values and residual transform coefficients. More specifically, the CABAC entropy decoding method can receive a bin corresponding to each syntax element in the bit stream, determine a context model using decoding target syntax element information, decoding information of a decoding target block, or information of a symbol/bin decoded in a previous stage, and perform arithmetic decoding on the bin by predicting a probability of occurrence of a bin according to the determined context model, and generate a symbol corresponding to the value of each syntax element. In this case, the CABAC entropy decoding method may update the context model using the decoded symbol/bin information for a context model of a next symbol/bin after determining the context model. The prediction-related information among the information decoded by the entropy decoder 310 may be provided to the predictor (the inter-predictor 332 and the intra-predictor 331), and the residual value on which an entropy decoding has been performed in the entropy decoder 310, i.e., the quantized transform coefficients and related parameter information, may be output to the residual processor 320. The residual processor 320 may derive the residual signal (the residual block, the residual samples, the residual sample array). Furthermore, filtering information among information decoded by entropy decoder 310 may be provided to filter 350. However, a receiver (not shown) for receiving a signal output from the encoding apparatus may be further configured as an internal/external element of decoding apparatus 300, or the receiver may be a component of entropy decoder 310. However, the decoding apparatus according to the present disclosure may be referred to as a video/image/picture decoding apparatus, and the decoding apparatus may be classified into an information decoder (video/image/picture information decoder) and a sample decoder (video/image/picture sample decoder). The information decoder may include entropy decoder 310, and the sample decoder may include at least one of dequantizer 321, inverse transformer 322, adder 340, filter 350, memory 360, interpredictor 332, and intrapredictor 331.

[069] The dequantizer 321 may dequantize the quantized transform coefficients and output the transform coefficients. The dequantizer 321 may rearrange the quantized transform coefficients in the form of a two-dimensional block form. In this case, the rearrangement may be performed based on the coefficient scan order performed in the encoding apparatus. The dequantizer 321 may perform dequantization on the quantized transform coefficients using a quantization parameter (e.g., quantization step size information) and obtain transform coefficients.

[070] The inverse transformer 322 inversely transforms the transform coefficients to obtain a residual signal (residual block, residual sample array).

[071] The predictor may perform a prediction on the current block and generate a predicted block including prediction samples for the current block. The predictor may determine whether intra-prediction or inter-prediction is applied to the current block based on information in the prediction output from the entropy decoder 310, and may determine a specific intra-/inter-prediction mode.

[072] The predictor 320 may generate a prediction signal based on various prediction methods described later. For example, the predictor may not only apply intra-prediction or inter-prediction to predict a block, but may also simultaneously apply intra-prediction and inter-prediction. This may be referred to as combined inter- and intra-prediction (CIIP). Furthermore, the predictor may rely on a block copy (IBC) intra-prediction mode or a pallet mode for predicting a block. The IBC prediction mode or pallet mode may be used for image/video coding of game content or the like, e.g., on-screen content (SCC) coding. IBC basically performs prediction on the current picture, but may be performed similarly to inter-prediction characterized in that a reference block is derived on the current picture. That is, IBC may use at least one of the inter-prediction techniques described in the present disclosure. Pallet mode can be considered as an example of intracoding or intraprediction. When pallet mode is applied, a sample value in a figuration can be signaled based on the information in the pallet table and the pallet index.

[073] The intrapredictor 331 may predict the current block by referring to samples in the current picture. The referred samples may be located in the vicinity of the current block or may be located apart according to the prediction mode. In intraprediction, the prediction modes may include a plurality of non-directional modes and a plurality of directional modes. The intrapredictor 331 may determine the prediction mode applied to the current block using a prediction mode applied to a neighboring block.

[074] The interpredictor 332 may derive the predicted block for the current block based on a reference block (reference sample array) specified by a motion vector in a reference picture. In this case, in order to reduce the amount of motion information transmitted in the interprediction mode, the motion information may be predicted in units of blocks, subblocks, or samples based on the correlation of motion information between the neighboring block and the current block. The motion information may include a motion vector and a reference picture index. The motion information may further include interprediction direction information (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of interprediction, the neighboring block may include a spatial neighboring block present in the current picture and a temporal neighboring block present in the reference picture. For example, the interpredictor 332 may configure a candidate list of motion information based on neighboring blocks and derive a motion vector of the current block and/or a reference figuration index based on the received candidate selection information. The interprediction may be performed based on multiple prediction modes, and the prediction information may include information indicating an interprediction mode for the current block.

[075] The adder 340 may generate a reconstructed signal (reconstructed pattern, reconstructed block, reconstructed sample array) by adding the obtained residual signal to the prediction signal (predicted block, predicted sample array) output from the predictor (including the inter-predictor 332 and/or the intra-predictor 331). If there is no residual for the block to be processed, such as when the skip mode is applied, the predicted block may be used as the reconstructed block.

[076] The adder 340 may be referred to as a reconstructor or a reconstructed block generator. The generated reconstructed signal may be used for intraprediction of a next block to be processed in the current picture, may be output through filtering as described below, or may be used for interprediction of a next picture.

[077] However, a luma mapping with chroma scaling (LMCS) can be applied in the figuration decoding process.

[078] Filter 350 may improve subjective/objective image quality by applying filtering to the reconstructed signal. For example, filter 350 may generate a modified reconstructed image by applying various filtering methods to the reconstructed image and store the modified reconstructed image in memory 360, specifically, a DPB of memory 360. The various filtering methods may include, for example, deblocking filtering, an adaptive sample shift, an adaptive loop filter, a bilateral filter, and the like.

[079] The reconstructed (modified) figuration stored in the DPB of memory 360 may be used as a reference figuration in interpredictor 332. Memory 360 may store the motion information of the block from which the motion information in the current figuration is derived (or decoded) and/or the motion information of blocks in the figuration that have already been reconstructed. The stored motion information may be transmitted to interpredictor 260 for use as the motion information of the spatial neighboring block or the motion information of the temporal neighboring block. Memory 360 may store reconstructed samples of reconstructed blocks in the current figuration and transfer the reconstructed samples to intrapredictor 331.

[080] In the present disclosure, the embodiments described in the filter 260, the interpredictor 221, and the intrapredictor 222 of the encoding apparatus 200 may be the same or respectively applied to correspond to the filter 350, the interpredictor 332, and the intrapredictor 331 of the decoding apparatus 300. The same may apply to the unit 332 and the intrapredictor 331.

[081] In the present disclosure, at least one of quantization/inverse quantization and/or transform/inverse transform may be omitted. When quantization/inverse quantization is omitted, the quantized transform coefficients may be referred to as transform coefficients. When transform/inverse transform is omitted, the transform coefficients may be referred to as coefficients or residual coefficients, or may be referred to as transform coefficients for the sake of uniformity of expression.

[082] In the present disclosure, a quantized transform coefficient and a transform coefficient may be referred to as a transform coefficient and a scaled transform coefficient, respectively. In this case, the residual information may include information about transform coefficient(s), and the information about transform coefficient(s) may be signaled via a residual coding syntax. The transform coefficients may be derived based on the residual information (or information about the transform coefficient(s), and the scaled transform coefficients may be derived by inversely transforming (scaling) the transform coefficients. The residual samples may be derived based on inversely transforming (transforming) the scaled transform coefficients. This may also be applied/expressed elsewhere in the present disclosure.

[083] As described above, the encoding apparatus may perform various encoding methods such as exponential Golomb, context adaptive variable length coding (CAVLC), and context adaptive binary arithmetic coding (CABAC). Furthermore, the decoding apparatus may decode information in a bit stream based on an encoding method such as exponential Golomb coding, CAVLC, or CABAC, and output a value of a syntax element required for image reconstruction and quantized values of transform coefficients related to residuals.

[084] For example, the encoding methods described above can be performed as described below.

[085] Figure 4 shows, by way of example, a context-adaptive binary arithmetic coding (CABAC) for encoding a syntax element. For example, in the CABAC encoding process, when an input signal is a syntax element rather than a binary value, the encoding apparatus can convert the input signal into a binary value by binarizing the value of the input signal. Furthermore, when the input signal is already a binary value (i.e., when the value of the input signal is a binary value), binarization cannot be performed and may be bypassed. In this document, each binary number 0 or 1 that constitutes a binary value may be referred to as a bin. For example, if a binary string after binarization is 110, each 1, 1, and 0 is referred to as a bin. The bin(s) for a syntax element may indicate a value of the syntax element.

[086] Subsequently, the binarized bins of the syntax element may be input to a regular encoding engine or a bias encoding engine. The regular encoding engine of the encoding apparatus may allocate a context model that reflects a probability value to the corresponding bin, and may encode the corresponding bin based on the allocated context model. The regular encoding engine of the encoding apparatus may update a context model for each bin after performing encoding on each bin. A bin encoded as described above may be referred to as a context-encoded bin.

[087] However, when binarized syntax element bins are input to the branch coding engine, they may be encoded as follows. For example, the branch coding engine of the coding apparatus omits a procedure for estimating a probability with respect to an input bin and a procedure for updating a probability model applied to the bin after encoding. When branch coding is applied, the coding apparatus may encode the input bin by applying a uniform probability distribution instead of allocating a context model, thereby improving an encoding rate. The bin encoded as described above may be referred to as a branch bin.

[088] An entropy decoding may represent a process of performing the same process as the entropy encoding described above in reverse order.

[089] For example, when a syntax element is decoded based on a context model, the decoding apparatus may receive a bin corresponding to the syntax element via a bit stream, determine a context model using the syntax element, and decode information of a decoding target block or a neighboring block or information of a symbol/bin decoded at a previous stage, predict an occurrence probability of the received bin according to the determined context model, and perform an arithmetic decoding on the bin to derive a value of the syntax element. Subsequently, a context model of a bin that is next decoded may be updated with the determined context model.

[090] Similarly, for example, when a syntax element is decoded by branching, the decoding apparatus may receive a bin corresponding to the syntax element via a bit stream, and decode the input bin by applying a uniform probability distribution. In this case, the procedure of the decoding apparatus for deriving the context model of the syntax element and the procedure for updating the context model applied to the bin after decoding may be omitted.

[091] As described previously, residual samples may be derived as quantized transform coefficients through transform and quantization processes. Quantized transform coefficients may also be referred to as transform coefficients. In this case, the transform coefficients in a block may be signaled in the form of residual information. The residual information may include a residual coding syntax. That is, the encoding apparatus may configure a residual coding syntax with residual information, encode it, and output it in the form of a bit stream, and the decoding apparatus may decode the residual coding syntax from the bit stream and derive residual (quantized) transform coefficients. The residual coding syntax may include syntax elements representing whether a transform was applied to the corresponding block, a location of a last effective transform coefficient in the block, whether an effective transform coefficient exists in the sub-block, a size/sign of the effective transform coefficient, and the like, as will be described later.

[092] For example, the syntax elements related to encoding/decoding residual data can be represented as shown in the following table. [Table 1]

[093] transform_skip_flag indicates whether a transform is skipped in an associated block. transform_skip_flag may be a syntax element of a transform skip flag. The associated block may be a coding block (CB) or a transform block (TB). Referring to transform (and quantization) and residual coding procedures, CB and TB may be used interchangeably. For example, as described above, residual samples may be derived for CB, and (quantized) transform coefficients may be derived via transform and quantization for the residual samples, and via the residual coding procedure, information (e.g., syntax elements) that efficiently indicate a position, magnitude, sign, etc. of the (quantized) transform coefficients may be generated and flagged. The quantized transform coefficients may simply be referred to as transform coefficients. In general, when the CB is not larger than a maximum TB, a CB size can be equal to a TB size, and in this case a target block to be transformed (and quantized) and residually encoded can be referred to as either a CB or a TB. However, when the CB is larger than the maximum TB, a target block to be transformed (and quantized) and residually encoded can be referred to as a TB. Hereinafter, it will be described that syntax elements related to residual coding are signaled in units of transform blocks (TBs), but this is an example and TB can be used interchangeably with coding blocks (CBs) as described above.

[094] However, syntax elements that are flagged after the transform omission flag is flagged may be the same as the syntax elements revealed in Table 2 and/or Table 3 below, and detailed descriptions of the syntax elements will be described below. [Table 2]

[095] According to the present embodiment, as shown in Table 1, a residual encoding may be split according to a value of the transform_skip_flag syntax element of the transform omit flag. That is, a different syntax element may be used for residual encoding based on the value of the transform omit flag (based on whether the transform is omitted). The residual encoding used when transform omit is not applied (i.e., when the transform is applied) may be referred to as regular residual encoding (RRC), and the residual encoding used when transform omit is applied (i.e., when the transform is not applied) may be referred to as transform omit residual encoding (TSRC). Likewise, regular residual encoding may be referred to as general residual encoding. Similarly, regular residual encoding may be referred to as a regular residual encoding syntax structure, and transform omit residual encoding may be referred to as a transform omit residual encoding syntax structure. Table 2 above can show a residual encoding syntax element when a value of transform_skip_flag is 0, that is, when the transform is applied, and Table 3 above can show a residual encoding syntax element when the value of transform_skip_flag is 1, that is, when the transform is not applied.

[096] Specifically, for example, the transform omit flag indicating whether to omit the transform from the transform block can be analyzed, and it can be determined whether the transform omit flag is 1. If the value of the transform omit flag is 0, as shown in Table 2, the syntax elements last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, last_sig_coeff_y_suffix, sb_coded_flag, sig_coeff_flag, abs_level_gtx_flag, par_level_flag, abs_remainder, coeff_sign_flag, and/or dec_abs_level for a residual coefficient of the transform block can be analyzed, and the residual coefficient can be derived based on the syntax elements. In this case, syntax elements can be sequentially parsed, and a parsing order can be changed. Additionally, abs_level_gtx_flag can represent abs_level_gt1_flag and/or abs_level_gt3_flag. For example, abs_level_gtx_flag[n][0] can be an example of a first transform coefficient level flag (abs_level_gt1_flag), and abs_level_gtx_flag[n][1] can be an example of a second transform coefficient level flag (abs_level_gt3_flag).

[097] Referring to Table 2 above, last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, last_sig_coeff_y_suffix, sb_coded_flag, sig_coeff_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag, abs_remainder, coeff_sign_flag and/or dec_abs_level can be encoded/decoded. However, sb_coded_flag can be represented as coded_sub_block_flag.

[098] In one embodiment, the encoding apparatus may encode position information (x, y) of the last non-zero transform coefficient in a transform block based on the syntax elements last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, and last_sig_coeff_y_suffix. More specifically, last_sig_coeff_x_prefix represents a prefix of a column position of a last significant coefficient in a scan order within the transform block, last_sig_coeff_y_prefix represents a prefix of a row position of the last significant coefficient in the scan order within the transform block, last_sig_coeff_x_suffix represents a suffix of a column position of the last significant coefficient in the scan order within the transform block, and last_sig_coeff_y_suffix represents a suffix of a row position of the last significant coefficient in the scan order within the transform block. In this document, the significant coefficient may represent a non-zero coefficient. Furthermore, the scan order may be a right diagonal scan order. Alternatively, the scan order may be a horizontal scan order or a vertical scan order. The scan order can be determined based on whether intra/inter prediction is applied to a target block (a CB or a CB including a TB) and/or a specific intra/inter prediction mode.

[099] Subsequently, the coding apparatus may divide the transform block into 4x4 sub-blocks, and then indicate whether there is a non-zero coefficient in the current sub-block using a 1-bit coded_sub_block_flag syntax element for each 4x4 sub-block.

[0100] If a value of coded_sub_block_flag is 0, there is no more information to be transmitted, and therefore the encoding apparatus may terminate the encoding process on the current sub-block. Conversely, if the value of coded_sub_block_flag is 1, the encoding apparatus may continuously perform the encoding process on sig_coeff_flag. Since the sub-block including the last non-zero coefficient does not require encoding for coded_sub_block_flag and the sub-block including the DC information of the transform block has a high probability of including the non-zero coefficient, coded_sub_block_flag may not be encoded and a value thereof may be assumed to be 1.

[0101] If the value of coded_sub_block_flag is 1, and then it is determined that a non-zero coefficient exists in the current sub-block, the coding apparatus may encode sig_coeff_flag having a binary value according to the reverse scan order. The coding apparatus may encode the 1-bit syntax element sig_coeff_flag for each transform coefficient according to the scan order. If the value of the transform coefficient at the current scan position is not 0, the value of sig_coeff_flag may be 1. In the present document, in the case of a sub-block including the last non-zero coefficient, sig_coeff_flag does not need to be encoded for the last non-zero coefficient, so the coding process for the sub-block may be omitted. Level information encoding can be performed only when sig_coeff_flag is 1, and four syntax elements can be used in the level information encoding process. More specifically, each sig_coeff_flag[xC][yC] can indicate whether a level (value) of a corresponding transform coefficient at each transform coefficient position (xC, yC) in the current TB is non-zero. In one embodiment, sig_coeff_flag can correspond to an example of a syntax element of a significant coefficient flag that indicates whether a quantized transform coefficient is a non-zero significant coefficient.

[0102] A remaining level value after encoding for sig_coeff_flag can be derived as shown in the following equation. That is, the remAbsLevel syntax element indicating a level value to be encoded can be derived from the following equation. [Equation 1]

[0103] In this document, coeff means a real transform coefficient value.

[0104] Additionally, abs_level_gt1_flag may indicate whether or not remAbsLevel' of the corresponding scan position (n) is greater than 1. For example, when the value of abs_level_gt1_flag is 0, the absolute value of the transform coefficient of the corresponding position may be 1. Furthermore, when the value of abs_level_gt1_flag is 1, remAbsLevel indicating the level value to be encoded later may be updated as shown in the following equation. [Equation 2]

[0105] Furthermore, the least significant coefficient (LSB) value of remAbsLevel described in Equation 2 described above may be encoded as in Equation 3 below via par_level_flag. [Equation 3]

[0106] In this document, par_level_flag[n] may indicate a parity of a transform coefficient level (value) at a scan position n.

[0107] A transform coefficient level value remAbsLevel that is to be encoded after performing par_level_flag encoding can be updated as shown below in the following equation. [Equation 4]

[0108] abs_level_gt3_flag can indicate whether or not remAbsLevel' of the corresponding scan position (n) is greater than 3. Encoding for abs_remainder can be performed only in a case where rem_abs_gt3_flag is equal to 1. A relationship between the current transform coefficient value coeff and each syntax element can be as shown below in the following equation. [Equation 5]

[0109] Additionally, the following table indicates examples related to Equation 5 described above. [Table 4]

[0110] In this document, |coeff| indicates a transform coefficient level (value) and may also be indicated as an AbsLevel for a transform coefficient. Additionally, a sign of each coefficient may be encoded using coeff_sign_flag, which is a 1-bit symbol.

[0111] Similarly, if the value of the transform omit flag is 1 as shown in Table 3, syntax elements sb_coded_flag, sig_coeff_flag, coeff_sign_flag, abs_level_gtx_flag, par_level_flag, and/or abs_remainder for a residual coefficient of the transform block can be parsed, and the residual coefficient can be derived based on the syntax elements. In this case, the syntax elements can be sequentially parsed, and a parsing order can be changed. In addition, abs_level_gtx_flag can represent abs_level_gt1_flag, abs_level_gt3_flag, abs_level_gt5_flag, abs_level_gt7_flag, and/or abs_level_gt9_flag. For example, abs_level_gtx_flag[n][j] can be a flag indicating whether an absolute value or a level (a value) of a transform coefficient at scan position n is greater than (j<<1)+1. The condition (j<<1)+1 can optionally be replaced by a specific threshold such as a first threshold, a second threshold, or the like.

[0112] However, CABAC provides high performance, but disadvantageously has poor throughput performance. This is caused by a regular encoding mechanism of CABAC. Regular encoding (i.e., encoding via the regular encoding mechanism of CABAC) shows high data dependency since it uses a probability state and range updated via encoding a previous bin, and it may take a long time to read a probability range and determine a current state. The throughput problem of CABAC can be solved by limiting the number of bins encoded per context. For example, as shown in Table 2 above, a sum of bins used to express sig_coeff_flag, abs_level_gt1_flag, par_level_flag, and abs_level_gt3_flag can be limited to the number of bins depending on a size of a corresponding block. Similarly, for example, as shown in Table 3 described above, a sum of bins used to express sig_coeff_flag, coeff_sign_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag abs_level_gt5_flag, abs_level_gt7_flag, abs_level_gt9_flag can be limited to the number of bins depending on a size of a corresponding block. For example, if the corresponding block is a 4x4 block, the sum of bins for sig_coeff_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag or sig_coeff_flag, coeff_sign_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag abs_level_gt5_flag, abs_level_gt7_flag, abs_level_gt9_flag can be limited to 32 (or, for example, 28), and if the corresponding block is a 2x2 block, the sum of bins for sig_coeff_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag can be limited to 8 (or, for example, 7). The limited number of bins can be represented by remBinsPass1 or RemCcbs. Or, for example, for higher CABAC throughput, the number of context-encoded bins can be limited to a block (CB or TB) including a target CG. In other words, the number of context-encoded bins can be limited in units of blocks (CB or TB). For example, when the current block size is 16x16, the number of context-encoded bins for the current block can be limited to 1.75 times the number of pixels in the current block, i.e. 448, regardless of the current CG.

[0113] In this case, if all context-coded bins to which the number is limited are used when a context element is coded, the coding apparatus may binarize the remaining coefficients by a coefficient binarization method as described below, instead of using context coding, and may perform bypass coding. In other words, for example, if the number of context-coded bins that are coded for CG 4x4 is 32 (or, for example, 28), or if the number of context-coded bins that are coded for CG 2x2 is 8 (or, for example, 7), sig_coeff_flag, abs_level_gt1_flag, par_level_flag, abs_level_gt3_flag that are coded with the context-coded bin may not be coded any further, and may be coded directly to dec_abs_level. Or, for example, when the number of context-coded bins encoded for a 4x4 block is 1.75 times the number of pixels of the entire block, i.e., when limited to 28, sig_coeff_flag, abs_level_gt1_flag, par_level_flag, and abs_level_gt3_flag encoded as context-coded bins may no longer be encoded, and may be directly encoded as dec_abs_level as shown in Table 5 below.

[0114] A |coeff| value can be derived based on dec_abs_level. In this case, a transform coefficient value, i.e., |coeff|, can be derived as shown in the following equation. [Equation 6]

[0115] In addition, coeff_sign_flag may indicate a sign of a transform coefficient level at a corresponding scan position n. That is, coeff_sign_flag may indicate the sign of the transform coefficient at the corresponding scan position n.

[0116] Figure 5 shows an example of transform coefficients in a 4x4 block.

[0117] The 4x4 block of Figure 5 represents an example of quantized coefficients. The block of Figure 5 may be a 4x4 transform block, or a 4x4 sub-block of an 8x8, 16x16, 32x32, or 64x64 transform block. The 4x4 block of Figure 5 may represent a luma block or a chroma block.

[0118] However, as described above, when an input signal is not a binary value but a syntax element, the encoding apparatus may transform the input signal into a binary value by binarizing a value of the input signal. Further, the decoding apparatus may decode the syntax element to derive a binarized value (e.g., a binarized bin) of the syntax element, and may debinarize the binarized value to derive a value of the syntax element. The binarization process may be performed as a truncated rice (TR) binarization process, a kth order Exp-Golomb (EGk) binarization process, a bounded kth order Exp-Golomb (bounded EGk), a fixed length (FL) binarization process, or the like. Furthermore, the debinarization process may represent a process performed based on the TR binarization process, EGk binarization process, or FL binarization process to derive the value of the syntax element.

[0119] For example, the TR binarization process can be performed as follows.

[0120] An input of the TR binarization process may be cMax and cRiceParam for a syntax element and a request for TR binarization. Additionally, an output of the TR binarization process may be a TR binarization for symbolVal which is a value corresponding to a bin string.

[0121] Specifically, for example, in the presence of a suffix bin string for a syntax element, a TR bin string for the syntax element may be a concatenation of a prefix bin string and the suffix bin string, and in the absence of the suffix bin string, the TR bin string for the syntax element may be the prefix bin string. For example, the prefix bin string may be derived as described below.

[0122] A symbolVal prefix value for the syntax element can be derived as shown in the following equation. [Equation 7]

[0123] In this document, prefixVal may denote a prefix value of symbolVal. A prefix (i.e., a prefix bin string) of the syntax element's TR bin string may be derived as described below.

[0124] For example, if prefixVal is less than cMax >> cRiceParam, the prefix bin string may be a bit string of length prefixVal+1, indexed by binIdx. That is, if prefixVal is less than cMax >> cRiceParam, the prefix bin string may be a bit string whose number of bits is prefixVal+1, indicated by binIdx. A bin for binIdx less than prefixVal may be equal to 1. Additionally, a bin for the same binIdx as prefixVal may be equal to 0.

[0125] For example, a bin string derived through unary binarization for prefixVal might be as shown in the following table.

[0126] However, if prefixVal is not less than cMax >> cRiceParam, the prefix bin string may be a bit string whose length is cMax >> cRiceParam and all bits are 1.

[0127] Additionally, if cMax is greater than symbolVal and if cRiceParam is greater than 0, a suffix bin string of a TR bin string may be present. For example, the suffix bin string may be derived as described below.

[0128] A symbolVal suffix value for the syntax element can be derived as shown in the following equation. [Equation 8]

[0129] In this document, suffixVal may denote a suffix value of symbolVal.

[0130] A suffix of a TR bin string (i.e., a suffix bin string) may be derived based on a FL binarization process for suffixVal whose cMax value is (1 << cRiceParam)-1.

[0131] However, if a value of an input parameter, i.e., cRiceParam, is 0, the binarization of TR may be a precisely truncated unary binarization, and may always use the same cMax value as a maximum possible value of a syntax element to be decoded.

[0132] Furthermore, for example, the binarization process of EGk may be performed as follows. A syntax element encoded with ue(v) may be a syntax element subjected to Exp-Golomb encoding.

[0133] For example, a 0-th order Exp-Golomb (EG0) binarization process can be performed as follows.

[0134] A parsing process for the syntax element may begin by reading a bit including a first non-zero bit starting at a current position in a bit stream and counting the number of leading bits equal to 0. The process may be represented as shown in the following table. [Table 7]

[0135] Additionally, a 'codeNum' variable can be derived as shown in the following equation. [Equation 9]

[0136] In this document, a value returned from read_bits(leadingZeroBits), i.e., a value indicated by read_bits(leadingZeroBits), may be interpreted as a binary representation of an integer not assigned to a most significant bit recorded first.

[0137] A structure of an Exp-Golomb code in which a bit string is divided into a “prefix” bit and a “suffix” bit can be represented as shown in the following table. Table 8]

[0138] The “prefix” bit may be a bit parsed as described above to compute leadingZeroBits, and may be represented by a 0 or 1 from a bit string in Table 8. That is, the bit string revealed by a 0 or 1 in Table 8 above may represent a prefix bit string. The “suffix” bit may be a bit parsed in the codeNum computation, and may be represented by xi in Table 8 above. That is, a bit string revealed as xi in Table 8 above may represent a suffix bit string. In this document, i may be a value in the range LeadingZeroBits-1. Furthermore, each xi may be equal to either 0 or 1.

[0139] A bit string assigned to codeNum may be as shown in the following table. Table 9]

[0140] If a syntax element descriptor is ue(v), that is, if the syntax element is encoded with ue(v), a value of the syntax element may be equal to codeNum.

[0141] Furthermore, for example, the binarization process of EGk can be carried out as follows.

[0142] An input to the EGk binarization process may be a request for EGk binarization. Furthermore, the output of the EGk binarization process may be EGk binarization to symbolVal, i.e., a value corresponding to a bin string.

[0143] A bit string of the binarization process from EGk to symbolVal can be derived as follows. Table 10]

[0144] Referring to Table 10 above, a binary value X may be added to one end of a bin chain through each insertion of put(X). In this document, X may be 0 or 1.

[0145] Furthermore, for example, the limited EGk binarization process can be carried out as follows.

[0146] An input of the bounded EGk binarization process may be a request for, a rice parameter riceParam, log2TransformRange as a variable representing a binary logarithm of a maximum value, and maxPreExtLen as a variable representing a maximum prefix extension length. Additionally, an output of the bounded EGk binarization process may be a bounded EGk binarization for symbolVal as a value corresponding to an empty string.

[0147] The bit string of the bounded EGk binarization process for symbolVal can be derived as follows. [Table 11]

[0148] Furthermore, for example, the FL binarization process can be performed as follows.

[0149] An input of the FL binarization process may be a request for FL binarization and cMax for the syntax element. Additionally, an output of the FL binarization process may be a FL binarization for symbolVal as a value corresponding to a bin string.

[0150] A binarization of FL may be configured using a bit string whose number of bits has a fixed length of symbolVal. In this document, the fixed length bit may be an unsigned integer bit string. That is, a bit string for symbolVal as a symbol value may be derived via binarization of FL, and a bit length (i.e., the number of bits) of the bit string may be a fixed length.

[0151] For example, the fixed length can be derived as shown in the following equation. [Equation 10]

[0152] Bin indexing for FL binarization may be a method that uses a regularly increasing value from a most significant bit to a least significant bit. For example, a bin index related to the most significant bit may be binIdx = 0.

[0153] However, for example, a binarization process for an abs_remainder syntax element in the residual information can be performed as follows.

[0154] An input to the binarization process for abs_remainder may be a request for binarization of a syntax element abs_remainder[n], a color component cIdx, and a luma position (x0, y0). The luma position (x0, y0) may indicate a top left sample of a current luma transform block based on the top left luma sample of a figuration.

[0155] An output of the binarization process for abs_remainder may be a binarization of abs_remainder (i.e., a binarized bin string of abs_remainder). The bin strings available to abs_remainder may be derived through the binarization process.

[0156] A rice parameter cRiceParam for abs_remainder[n] may be derived through a rice parameter derivation process performed by inputting the color component cIdx and the luma position (x0, y0), the coefficient scan position (xC, yC), log2TbWidth, which is the binarization logarithm of the transform block width, and log2TbHeight, which is the binarization logarithm of the transform block height. A detailed description of the rice parameter derivation process will be described later.

[0157] Additionally, for example, cMax for abs_remainder[n] to be currently encoded can be derived based on the rice parameter cRiceParam. cMax can be derived as shown in the following equation. [Equation 11]

[0158] However, the binarization for abs_remainder, i.e., a bin string for abs_remainder, may be a concatenation of a prefix bin string and a suffix bin string in the presence of the suffix bin string. Furthermore, in the absence of the suffix bin string, the bin string for abs_remainder may be the prefix bin string.

[0159] For example, the prefix bin string can be derived as described below.

[0160] A prefix value prefixVal of abs_remainder[n] can be derived as shown in the following equation. [Equation 12]

[0161] A bin string prefix (i.e., a prefix bin string) of abs_remainder[n] can be derived through a binarization process from TR to prefixVal, where cMax and cRiceParam are used as an input.

[0162] If the prefix bin string is identical to a bit string in which all bits are 1 and a bit length is 6, a suffix bin string of the abs_remainder[n] bin string may exist, and may be derived as described below.

[0163] The parameter derivation process from rice to dec_abs_level[n] can be as follows.

[0164] An input of the rice parameter derivation process may be a color component index cIdx, a luma position (x0, y0), a current coefficient scan position (xC, yC), log2TbWidth as a binary logarithm of a width of a transform block, and log2TbHeight as a binary logarithm of a height of the transform block. The luma position (x0, y0) may indicate a top left sample of a current luma transform block based on a top left luma sample of a figuration. Additionally, an output of the rice parameter derivation process may be the rice parameter cRiceParam.

[0165] For example, a variable locSumAbs may be derived similarly to the pseudocode disclosed in the following table, based on an array AbsLevel[x][y] for a transform block having the given component index cIdx and the upper left luma position (x0, y0). [Table 12]

[0166] Then, based on the given locSumAbs variable, the rice parameter cRiceParam can be derived as shown in the following table. [Table 13]

[0167] Similarly, for example, in the process of deriving parameter from rice for abs_remainder[n], baseLevel can be set to 4.

[0168] Alternatively, for example, the rice parameter cRiceParam may be determined based on whether a transform omission is applied to a current block. That is, if a transform is not applied to a current TB including a current CG, in other words, if transform omission is applied to the current TB including the current CG, the rice parameter cRiceParam may be derived as being 1.

[0169] Similarly, a suffix value suffixVal of abs_remainder can be derived as shown in the following equation. [Equation 13]

[0170] A suffix bin string from the abs_remainder bin string may be derived via a bounded EGk binarization process for the suffixVal where k is set to cRiceParam+1, riceParam is set to cRiceParam, and log2TransformRange is set to 15, and maxPreExtLen is set to 11.

[0171] However, for example, a binarization process for a syntax element dec_abs_level in the residual information can be performed as follows.

[0172] An input to the binarization process for dec_abs_level may be a request for binarization of a dec_abs_level[n] syntax element, a color component cIdx, a luma position (x0, y0), a current coefficient scan position (xC, yC), log2TbWidth as a binary logarithm of a width of a transform block, and log2TbHeight as a binary logarithm of a height of the transform block. The luma position (x0, y0) may indicate a top left sample of a current luma transform block based on a top left luma sample of a figuration.

[0173] An output of the binarization process for dec_abs_level may be a binarization of dec_abs_level (i.e., a binarized bin string of dec_abs_level). Available bin strings for dec_abs_level may be derived through the binarization process.

[0174] A rice parameter cRiceParam for dec_abs_level[n] may be derived through a rice parameter derivation process performed with an input of the color component cIdx, the luma position (x0, y0), the current coefficient scan position (xC, yC), log2TbWidth as the binary logarithm of the transform block width, and log2TbHeight as the binary logarithm of the transform block height. The rice parameter derivation process will be described in detail below.

[0175] Additionally, for example, cMax for dec_abs_level[n] can be derived based on the rice parameter cRiceParam. cMax can be derived as shown in the following table. [Equation 14]

[0176] However, the binarization for dec_abs_level[n], i.e., a bin string for dec_abs_level[n], may be a concatenation of a prefix bin string and a suffix bin string in the presence of the suffix bin string. Furthermore, in the absence of the suffix bin string, the bin string for dec_abs_level[n] may be the prefix bin string.

[0177] For example, the prefix bin string can be derived as described below.

[0178] A prefix value prefixVal of dec_abs_level[n] can be derived as shown in the following equation. [Equation 15]

[0179] A bin string prefix (i.e., a prefix bin string) of dec_abs_level[n] can be derived through a binarization process from TR to prefixVal, where cMax and cRiceParam are used as an input.

[0180] If the prefix bin string is identical to a bit string where all bits are 1 and a bit length is 6, a suffix bin string of the dec_abs_level[n] bin string may exist, and may be derived as described below.

[0181] The parameter derivation process from rice to dec_abs_level[n] can be as follows.

[0182] An input to the rice parameter derivation process may be a color component index cIdx, a luma position (x0, y0), a current coefficient scan position (xC, yC), log2TbWidth as a binary logarithm of a width of a transform block, and log2TbHeight as a binary logarithm of a height of the transform block. The luma position (x0, y0) may indicate a top left sample of a current luma transform block based on a top left luma sample of a figuration. Additionally, an output of the rice parameter derivation process may be the rice parameter cRiceParam.

[0183] For example, a variable locSumAbs may be derived similarly to the pseudocode disclosed in the following table, based on an array AbsLevel[x][y] for a transform block having the given component index cIdx and the upper left luma position (x0, y0). [Table 14]

[0184] Then, based on the given locSumAbs variable, the rice parameter cRiceParam can be derived as shown in the following table. [Table 15]

[0185] Similarly, for example, in the process of deriving the rice parameter for dec_abs_level[n], baseLevel can be set to 0 and ZeroPos[n] can be derived as follows. [Equation 16]

[0186] Additionally, a suffix value suffixVal of dec_abs_level[n] can be derived as shown in the following equation. [Equation 17]

[0187] A suffix bin string from the bin string of dec_abs_level[n] may be derived via a bounded EGk binarization process for suffixVal where k is set to cRiceParam+1, truncSuffixLen is set to 15, and maxPreExtLen is set to 11.

[0188] However, RRC and TSRC may have the following differences.

[0189] - - For example, the Rice parameter cRiceParam of the abs_remainder[] and dec_abs_level[] syntax element in the RRC may be derived based on locSumAbs, the lookup table, and/or the baseLevel as described previously, but the Rice parameter cRiceParam of the abs_remainder[] syntax element in the TSRC may be derived as 1. That is, for example, when a transform omission is applied to the current block (e.g., current TB), the Rice parameter cRiceParam for abs_remainder[] of the TSRC for the current block may be derived as 1.

[0190] - Similarly, for example, referring to Table 3 and Table 4, in RRC, abs_level_gtx_flag[n][0] and/or abs_level_gtx_flag[n][1] may be flagged, but in TSRC, abs_level_gtx_flag[n][0], abs_level_gtx_flag[n][1], abs_level_gtx_flag[n][2], abs_level_gtx_flag[n][3], and abs_level_gtx_flag[n][4] may be flagged. In this document, abs_level_gtx_flag[n][0] may be expressed as abs_level_gt1_flag or a first coefficient level flag, abs_level_gtx_flag[n][1] may be expressed as abs_level_gt3_flag or a second coefficient level flag, abs_level_gtx_flag[n][2] may be expressed as abs_level_gt5_flag or a third coefficient level flag, abs_level_gtx_flag[n][3] may be expressed as abs_level_gt7_flag or a fourth coefficient level flag, and abs_level_gtx_flag[n][4] may be expressed as abs_level_gt9_flag or a fifth coefficient level flag. Specifically, the first coefficient level flag may be a flag for if a coefficient level is greater than a first threshold (e.g., 1), the second coefficient level flag may be a flag for if a coefficient level is greater than a second threshold (e.g., 3), the third coefficient level flag may be a flag for if a coefficient level is greater than a third threshold (e.g., 5), the fourth coefficient level flag may be a flag for if a coefficient level is greater than a fourth threshold (e.g., 7), the fifth coefficient level flag may be a flag for if a coefficient level is greater than a fifth threshold (e.g., 9). As described above, in TSRC, compared to RRC, abs_level_gtx_flag[n][0], abs_level_gtx_flag[n][1] and abs_level_gtx_flag[n][2], abs_level_gtx_flag[n][3], abs_level_gtx_flag[n][4] can be additionally including.

[0191] - Similarly, for example, in RRC, the syntax element coeff_sign_flag can be branch-encoded, but in TSRC, the syntax element coeff_sign_flag can be branch-encoded or context-encoded.

[0192] Furthermore, for a residual sample quantization process, a dependent quantization can be proposed. Dependent quantization can represent a method dependent on a value of a transform coefficient (value of a transform coefficient level) where a set of allowed reconstructed values for a current transform coefficient precedes the current transform coefficient in a reconstruction order. That is, for example, dependent quantization can be performed by (a) defining two scalar quantizers having different reconstruction levels, and (b) defining a process for transition between the scalar quantizers. Dependent quantization can have an effect where an allowed reconstructed vector is more concentrated in an N-dimensional vector space compared to the existing independent scalar quantization. In the present document, N can represent the number of transform coefficients of a transform block.

[0193] Figure 6 illustrates, by way of example, scalar quantizers being used in dependent quantization. Referring to Figure 6, the position of the enabled reconstructed levels can be designated by a quantization step size △. Referring to Figure 6, the scalar quantizers can be represented as Q0 and Q1. The scalar quantizer being used can be derived without being explicitly signaled from a bit stream. For example, the quantizer being used for the current transform coefficient can be determined by parities of the transform coefficient level preceding the current transform coefficient in the encoding/reconstruction order.

[0194] Figure 7 illustrates, by way of example, the state transition and quantizer selection for dependent quantization.

[0195] Referring to Figure 7, the transition between the two scalar quantizers Q0 and Q1 may be performed via a state machine having four states. The four states may have four different values (0, 1, 2, and 3). In the encoding/reconstructed order, the state for the current transform coefficient may be determined by the parities of the transform coefficient level before the current transform coefficient.

[0196] For example, in the case where a dequantization process for the transform block starts, the state for dependent quantization may be set to 0. Subsequently, the transform coefficients of the transform block may be reconstructed in the scan order (i.e., the same order as that of entropy decoding). For example, after the current transform coefficient is reconstructed, as illustrated in Figure 7, the state for dependent quantization may be updated. In the scan order, the dequantization process for the transform coefficient being reconstructed after the current transform coefficient is reconstructed may be performed based on an updated state. In Figure 7, k may represent a transform coefficient value, i.e., the value of the transform coefficient level value. For example, if k(current transform coefficient value) & 1 is 0 in a state where the current state is 0, the state can be updated to 0, while if k&1 is 1, the state can be updated to 2. Further, for example, if k&1 is 0 in a state where the current state is 1, the state can be updated to 2, while if k&1 is 1, the state can be updated to 0. Further, for example, if k&1 is 0 in a state where the current state is 2, the state can be updated to 1, while if k&1 is 1, the state can be updated to 3. Further, for example, if k&1 is 0 in a state where the current state is 3, the state can be updated to 3, while if k&1 is 1, the state can be updated to 1. Referring to Figure 7, if the state is either 0 or 1, the scalar quantizer being used in dequantization process can be Q0, and if the state is 2 or 3, the scalar quantizer being used in the dequantization process can be Q1. The transform coefficient can be dequantized by the scalar quantizer to the current state based on a quantization parameter to a reconstructed level of the transform coefficient.

[0197] However, the present disclosure proposes embodiments related to residual data coding. The embodiments being explained in the present disclosure may be combined with each other. In the residual data coding method as described above, regular residual coding (RRC) and transform omission residual coding (TSRC) may be present.

[0198] Of the two methods as described above, the residual data coding method for the current block can be determined based on the values of transform_skip_flag and sh_ts_residual_coding_disabled_flag as illustrated in Table 1. In the present document, the syntax element sh_ts_residual_coding_disabled_flag can represent whether TSRC is enabled. Correspondingly, if slice_ts_residual_coding_disabled_flag represents that TSRC is not enabled even in the case where transform_skip_flag represents transform omission, the syntax elements according to RRC can be flagged for the transform omission block. That is, if the value of transform_skip_flag is 0, or if the value of slice_ts_residual_coding_disabled_flag is 1, RRC can be used, while otherwise, TSRC can be used.

[0199] Although high coding efficiency can be achieved in specific applications (e.g., lossless coding and the like) by using slice_ts_residual_coding_disabled_flag, in the existing video/image standard, restrictions in a case where dependent quantization and slice_ts_residual_coding_disabled_flag are used together have not been proposed. That is, dependent quantization can be enabled at high level (e.g., sequence parameter set (SPS) syntax/video parameter set (VPS) syntax/decode parameter set (DPS) syntax/picture header syntax/slice header syntax) or at low level CU/TU), and if slice_ts_residual_coding_disabled_flag is 1, the dependent values of the dependent quantization state in RRC may perform unnecessary operation (i.e., operation according to dependent quantization) to degrade coding performance, or an unintended loss of coding performance may occur due to erroneous configuration in the coding apparatus. Correspondingly, the present embodiment proposes schemes for setting dependencies/constraints between two technologies of dependent quantization and residual coding (i.e., coding residual samples of a transform omission block in the current slice via RRC) in the case where slice_ts_residual_coding_disabled_flag = 1, which are used together to prevent unintentional coding loss or malfunction from occurring.

[0200] As an embodiment, the present disclosure proposes a method where slice_ts_residual_coding_disabled_flag ph_dep_quant_enabled_flag. For example, the syntax elements proposed in the present embodiment may be in the following table. [Table 16]

[0201] According to the present embodiment, slice_ts_residual_coding_disabled_flag may be flagged in the case where the value of ph_dep_quant_enabled_flag is 0. In the present document, ph_dep_quant_enabled_flag may represent whether dependent quantization is enabled. For example, if the value of ph_dep_quant_enabled_flag is 1, this may represent that dependent quantization is enabled, while if the value of ph_dep_quant_enabled_flag is 0, this may represent that dependent quantization is not enabled.

[0202] Correspondingly, according to the present embodiment, slice_ts_residual_coding_disabled_flag may be flagged only in the case where dependent quantization is not enabled, and in the case where dependent quantization is enabled, and therefore slice_ts_residual_coding_disabled_flag is not flagged, slice_ts_residual_coding_disabled_flag may be inferred to be 0. However, ph_dep_quant_enabled_flag and slice_ts_residual_coding_disabled_flag may be flagged to the figuration header syntax and/or the slice header syntax, or may be flagged to other high-level syntax (HLS) (e.g., SPS syntax/VPS syntax/DPS syntax) other than the figuration header syntax and the slice header syntax or at the low level (CU/TU). If ph_dep_quant_enabled_flag is flagged to a syntax other than the figuration header syntax, it may be called by another name. For example, ph_dep_quant_enabled_flag may be represented as sh_dep_quant_enabled_flag, sh_dep_quant_used_flag, or sps_dep_quant_enabled_flag.

[0203] Furthermore, the present disclosure proposes another embodiment for configuring dependencies/constraints between dependent quantization and residual coding (i.e., coding residual samples of the transform omission block in the current slice via RRC) in the case where slice_ts_residual_coding_disabled_flag = 1. For example, the present embodiment proposes a scheme for producing the state of dependent quantization not in use in coding the transform coefficient level value in the case where the value of slice_ts_residual_coding_disabled_flag is 1 in order to prevent unintentional coding loss or malfunction from occurring by using dependent quantization and residual coding (i.e., coding residual samples of the transform omission block in the current slice via RRC) in the case where slice_ts_residual_coding_disabled_flag = 1 together. The residual coding syntax according to the present embodiment may be as in the following table. [Table 17]

[0204] Referring to Table 17 as described previously, in the case where the value of ph_dep_quant_enabled_flag is 1, and the value of slice_ts_residual_coding_disabled_flag is 0, the Qstate can be derived, and the transform coefficient value (transform coefficient level) can be derived based on the Qstate. For example, referring to Table 17, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as ( 2 * AbsLevel[xC][yC] - (QState > 1 ? 1 : 0 )) * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] may be an absolute value of the transform coefficient derived based on the syntax elements of the transform coefficient, coeff_sign_flag[n] may be a syntax element of a sign flag representing the sign of the transform coefficient, and (QState > 1 ? 1 : 0) may represent 1 if the value of the state QState is greater than 1, that is, if the value of the state Qstate is 2 or 3, and may represent 0 if the value of the state Qstate is equal to or less than 1, that is, if the value of the state Qstate is 0 or 1.

[0205] Further, referring to Table 17 as described previously, if the value of slice_ts_residual_coding_disabled_flag is 1, the transform coefficient value (transform coefficient level) can be derived without using Qstate. For example, referring to Table 17, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as AbsLevel[xC][yC] * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] can be an absolute value of the transform coefficient derived based on the syntax elements of the transform coefficient, and coeff_sign_flag[n] can be a syntax element of a sign flag representing the sign of the transform coefficient.

[0206] Further, according to the present embodiment, if the value of slice_ts_residual_coding_disabled_flag is 1, the state of dependent quantization may not be used in encoding the level value of the transform coefficient, and the state update may also not be performed. For example, the residual coding syntax according to the present embodiment may be as in the following table. [Table 18]

[0207] Referring to Table 18 as described previously, if the value of ph_dep_quant_enabled_flag is 1, and the value of slice_ts_residual_coding_disabled_flag is 0, the Qstate may be updated. For example, if the value of ph_dep_quant_enabled_flag is 1, and the value of slice_ts_residual_coding_disabled_flag is 0, the QState may be updated as QStateTransTable[QState][AbsLevelPass1[xC][yC] & 1] or QStateTransTable[QState][AbsLevel[xC][yC] & 1]. Furthermore, if the value of slice_ts_residual_coding_disabled_flag is 1, a process of updating the Qstate may not be performed.

[0208] Further, referring to Table 18 as described previously, if the value of ph_dep_quant_enabled_flag is 1, and the value of slice_ts_residual_coding_disabled_flag is 0, the transform coefficient value (transform coefficient level) can be derived based on the QState. For example, referring to Table 18, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as ( 2 * AbsLevel[xC][yC] - (QState > 1 ? 1 : 0 )) * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] may be an absolute value of the transform coefficient derived based on the transform coefficient syntax elements, coeff_sign_flag[n] may be the sign flag syntax element representing the sign of the transform coefficient, and (QState > 1 ? 1 : 0) may represent 1 if the value of the state Qstate is greater than 1, that is, if the value of the state Qstate is 2 or 3, and may represent 0 if the value of the state Qstate is equal to or less than 1, that is, if the value of the state Qstate is 0 or 1.

[0209] Further, referring to Table 18 as described previously, if the value of slice_ts_residual_coding_disabled_flag is 1, the transform coefficient value (transform coefficient level) can be derived without using Qstate. For example, referring to Table 18, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as AbsLevel[xC][yC] * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] can be an absolute value of the transform coefficient derived based on the syntax elements of the transform coefficient, and coeff_sign_flag[n] can be a syntax element of a sign flag representing the sign of the transform coefficient.

[0210] Furthermore, the present disclosure proposes another embodiment for setting dependencies/constraints between dependent quantization and residual coding (i.e., coding residual samples of the transform skip block in the current slice via RRC) in the case where slice_ts_residual_coding_disabled_flag = 1. For example, the present embodiment proposes a scheme for adding constraints using a transform_skip_flag in a process of deriving the transform coefficient value (transform coefficient level) dependently on the state update or the state of dependent quantization in RRC. That is, the present embodiment proposes a scheme for producing the process of deriving the transform coefficient value (transform coefficient level) not in use dependently on the state update and/or the state of dependent quantization in RRC based on transform_skip_flag. The residual coding syntax according to the present embodiment may be as in the following Table. [Table 19]

[0211] Referring to Table 19 as described previously, if the value of ph_dep_quant_enabled_flag is 1, and the value of transform_skip_flag is 0, Qstate may be updated. For example, if the value of ph_dep_quant_enabled_flag is 1, and the value of transform_skip_flag is 0, Qstate may be updated as QStateTransTable[QState][AbsLevelPass1[xC][yC] & 1] or QStateTransTable[QState][AbsLevel[xC][yC] & 1]. Furthermore, if the value of transform_skip_flag is 1, the process of updating Qstate may not be performed.

[0212] Further, referring to Table 19 as described previously, if the value of ph_dep_quant_enabled_flag is 1, and the value of transform_skip_flag is 0, Qstate can be derived, and the transform coefficient value (transform coefficient level) can be derived based on QState. For example, referring to Table 19, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as ( 2 * AbsLevel[xC][yC] - (QState > 1 ? 1 : 0 )) * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] may be an absolute value of the transform coefficient derived based on the transform coefficient syntax elements, coeff_sign_flag[n] may be the sign flag syntax element representing the sign of the transform coefficient, and (QState > 1 ? 1 : 0) may represent 1 if the value of the state Qstate is greater than 1, that is, if the value of the state Qstate is 2 or 3, and may represent 0 if the value of the state Qstate is equal to or less than 1, that is, if the value of the state Qstate is 0 or 1.

[0213] Further, referring to Table 19 as described above, if the value of transform_skip_flag is 1, the transform coefficient value (transform coefficient level) can be derived without using Qstate. Correspondingly, in the case where residual data according to RRC are coded for the transform skip block, the transform coefficient value can be derived without using Qstate. For example, referring to Table 19, the transform coefficient level TransCoeffLevel[x0][y0][cIdx][xC][yC] can be derived as AbsLevel[xC][yC] * ( 1 - 2 * coeff_sign_flag[n] ). In this document, AbsLevel[xC][yC] may be an absolute value of the transform coefficient derived based on the transform coefficient syntax elements, and coeff_sign_flag[n] may be the sign flag syntax element representing the sign of the transform coefficient.

[0214] Furthermore, the present disclosure proposes several embodiments related to flagging the sh_ts_residual_coding_disabled_flag syntax element described above.

[0215] For example, as described previously, sh_ts_residual_coding_disabled_flag is a syntax element that defines whether TSRC is not enabled, and in the case where the transform omit block is not used, it may not be necessary for it to be flagged. That is, only in the case where the syntax element for whether the transform omit block is used represents that the transform omit block is used, it may be meaningful to flag sh_ts_residual_coding_disabled_flag.

[0216] Correspondingly, the present disclosure proposes an embodiment for flagging the sh_ts_residual_coding_disabled_flag only in the case where sps_transform_skip_enabled_flag is 1. The syntax according to the present embodiment is as in the following table. [Table 20]

[0217] Referring to Table 20, if sps_transform_skip_enabled_flag is 1, sh_ts_residual_coding_disabled_flag can be flagged, while if sps_transform_skip_enabled_flag is 0, sh_ts_residual_coding_disabled_flag cannot be flagged. In this document, for example, sps_transform_skip_enabled_flag can represent whether the transform skipping block is used. That is, for example, sps_transform_skip_enabled_flag can represent whether transform skipping is enabled. For example, if the value of sps_transform_skip_enabled_flag is 1, sps_transform_skip_enabled_flag can represent that the transform skip flag (transform_skip_flag) can be present in the transform unit syntax, whereas if the value of sps_transform_skip_enabled_flag is 0, sps_transform_skip_enabled_flag can represent that the transform skip flag is not present in the transform unit syntax. However, if sh_ts_residual_coding_disabled_flag is not flagged, it can be inferred that sh_ts_residual_coding_disabled_flag is 0. Furthermore, sps_transform_skip_enabled_flag described above may be flagged in SPS, or it may be flagged in other high-level syntaxes (VPS, PPS, figuration header syntax, and slice header syntax) that are not SPS, or low-level syntaxes (slice data syntax, coding unit syntax, and transform unit syntax). Furthermore, it may be flagged before slice_ts_residual_coding_disabled_flag.

[0218] Furthermore, the present disclosure proposes an embodiment where the previously described embodiments are combined with respect to the signaling of sh_ts_residual_coding_disabled_flag. For example, as per the following table, one may propose an embodiment for signaling sh_ts_residual_coding_disabled_flag. [Table 21]

[0219] Referring to Table 21, in the case where sps_transform_skip_enabled_flag is 1, or ph_dep_quant_enabled_flag is 0, sh_ts_residual_coding_disabled_flag can be flagged, and otherwise, sh_ts_residual_coding_disabled_flag cannot be flagged. However, in the case where sh_ts_residual_coding_disabled_flag is not flagged, sh_ts_residual_coding_disabled_flag can be inferred to be 0.

[0220] Furthermore, for example, a modality can be proposed to signal sh_ts_residual_coding_disabled_flag as in the following table. [Table 22]

[0221] Referring to Table 22, sh_ts_residual_coding_disabled_flag may be flagged to a figuration header. sh_ts_residual_coding_disabled_flag may be represented as ph_ts_residual_coding_disabled_flag. Further, referring to Table 22, ph_dep_quant_enabled_flag may be flagged to the figuration header.

[0222] For example, referring to Table 22, in the case where ph_dep_quant_enabled_flag is 0, and sps_transform_skip_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may be flagged, and otherwise, ph_ts_residual_coding_disabled_flag may not be flagged. However, in the case where ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag may be inferred to be 0.

[0223] In the existing video/image coding standard with respect to syntax elements described in embodiments of the present disclosure, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax, and sh_ts_residual_coding_disabled_flag may be flagged in the slice header syntax. In this regard, the present disclosure proposes an embodiment for flagging two syntax elements in the same high-level syntax or low-level syntax.

[0224] For example, one may propose an embodiment where both ph_dep_quant_enabled_flag and sh_ts_residual_coding_disabled_flag are flagged in the figuration header syntax. In this case, sh_ts_residual_coding_disabled_flag may be named as ph_ts_residual_coding_disabled_flag.

[0225] Furthermore, for example, one may propose an embodiment where both ph_dep_quant_enabled_flag and sh_ts_residual_coding_disabled_flag are flagged in the slice header syntax. In this case, ph_dep_quant_enabled_flag may be named as sh_dep_quant_enabled_flag, sh_dep_quant_used_flag or slice_dep_quant_enabled_flag.

[0226] Furthermore, for example, one may propose an embodiment where both ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in the same HLS, but ph_ts_residual_coding_disabled_flag is flagged only in the case where the value of ph_dep_quant_enabled_flag is 0. For example, an example where both ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in the figuration header syntax may be as in the following table. [Table 23]

[0227] Referring to Table 23, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax, and if the value of ph_dep_quant_enabled_flag is 0, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, while if the value of ph_dep_quant_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may not be flagged. For example, if ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag may be inferred to be 0.

[0228] However, the embodiment described above is an example, and one may propose an example, where ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in other high-level syntaxes (VPS, SPS, PPS, and slice header syntax) or low-level syntaxes (slice data syntax, coding unit syntax, and transform unit syntax) rather than the figuration header syntax.

[0229] Furthermore, for example, one can propose a modality, where both ph_ts_residual_coding_disabled_flag and ph_dep_quant_enabled_flag are flagged in the same HLS, but ph_dep_quant_enabled_flag is flagged only in the case where the value of ph_ts_residual_coding_disabled_flag is 0. [Table 24]

[0230] Referring to Table 24, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, and if the value of ph_ts_residual_coding_disabled_flag is 0, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax, while if the value of ph_ts_residual_coding_disabled_flag is 1, ph_dep_quant_enabled_flag may not be flagged. For example, if ph_dep_quant_enabled_flag is not flagged, ph_dep_quant_enabled_flag may be inferred to be 0.

[0231] However, the embodiment described above is an example, and one may propose an example where ph_ts_residual_coding_disabled_flag and ph_dep_quant_enabled_flag are flagged in other high-level syntaxes (VPS, SPS, PPS, and slice header syntax) or low-level syntaxes (slice data syntax, coding unit syntax, and transform unit syntax) rather than the figuration header syntax.

[0232] Furthermore, for example, one may propose an embodiment where the modalities described above are combined with each other. For example, one may propose an embodiment where both ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in the same HLS, but ph_ts_residual_coding_disabled_flag is flagged only in the case where the value of ph_dep_quant_enabled_flag is 0, or the value of sps_transform_skip_enabled_flag is 1. [Table 25]

[0233] Referring to Table 25, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax, and in the case where the value of ph_dep_quant_enabled_flag is 0, or the value of sps_transform_skip_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, and otherwise, ph_ts_residual_coding_disabled_flag may not be flagged. In this document, for example, sps_transform_skip_enabled_flag may represent whether the transform skipping block is used. That is, for example, sps_transform_skip_enabled_flag may represent whether transform skipping is enabled. For example, if the value of sps_transform_skip_enabled_flag is 1, sps_transform_skip_enabled_flag can represent that the transform skip flag (transform_skip_flag) can be present in the transform unit syntax, whereas if the value of sps_transform_skip_enabled_flag is 0, sps_transform_skip_enabled_flag can represent that the transform skip flag is not present in the transform unit syntax. For example, if ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag can be inferred to be 0.

[0234] Furthermore, for example, one may propose an embodiment where both ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in the same HLS (e.g., slice header syntax or the like), but ph_ts_residual_coding_disabled_flag is flagged only in the case where the value of ph_dep_quant_enabled_flag is 0, and the value of sps_transform_skip_enabled_flag is 1. [Table 26]

[0235] Referring to Table 26, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax, and in the case where the value of ph_dep_quant_enabled_flag is 0, and the value of sps_transform_skip_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, and otherwise, ph_ts_residual_coding_disabled_flag may not be flagged. For example, if ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag may be inferred to be 0.

[0236] Furthermore, for example, one can propose an embodiment where both ph_dep_quant_enabled_flag and ph_ts_residual_coding_disabled_flag are flagged in the same HLS, but ph_ts_residual_coding_disabled_flag is flagged only in the case where the value of v sps_transform_skip_enabled_flag is 1, and ph_dep_quant_enabled_flag is flagged only in the case where the value of ph_ts_residual_coding_disabled_flag is 0. [Table 27]

[0237] Referring to Table 27, if the value of sps_transform_skip_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, while if the value of ph_ts_residual_coding_disabled_flag is 0, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax. For example, if the value of sps_transform_skip_enabled_flag is 0, ph_ts_residual_coding_disabled_flag may not be flagged. For example, if ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag may be inferred to be 0. Furthermore, for example, if the value of ph_ts_residual_coding_disabled_flag is 1, ph_dep_quant_enabled_flag may not be flagged. For example, if ph_dep_quant_enabled_flag is not flagged, ph_dep_quant_enabled_flag may be inferred to be 0.

[0238] However, as described above, information (syntax elements) in a syntax table disclosed in the present disclosure may be included in the image/video information, configured/encoded by the encoding apparatus, and transferred to the decoding apparatus in the form of a bit stream. A decoding apparatus may analyze/decode the information (syntax elements) in the corresponding syntax table. The decoding apparatus may perform a block/image/video reconstruction procedure based on the decoded information.

[0239] Furthermore, the present disclosure proposes several embodiments related to flagging the sh_ts_residual_coding_disabled_flag syntax element described above.

[0240] For example, high coding efficiency can be achieved in a specific application (e.g., lossless coding, etc.) by using slice_ts_residual_coding_disabled_flag as described above, but in the existing video/image coding standard, a restriction is not proposed in the case where slice_ts_residual_coding_disabled_flag is used together with signal data hiding (SDH).

[0241] In this document the signal data hiding method may be as follows.

[0242] In deriving the transform coefficient, the sign of the transform coefficient may be derived based on a 1-bit sign flag (the previously described syntax element coeff_sign_flag). In this regard, SDH may indicate a technique for omitting an explicit flagging of coeff_sign_flag for the first significant transform coefficient in a sub-block/coefficient group (CG) in order to improve coding efficiency. In the present document, the value of coeff_sign_flag for the first significant transform coefficient may be derived based on the sum of absolute levels (i.e., absolute values) of the significant transform coefficients in the corresponding sub-block/coefficient group. That is, the sign of the first significant transform coefficient may be derived based on the sum of absolute levels of the significant transform coefficients in the corresponding sub-block/coefficient group. However, the significant transform coefficient can mean a nonzero transform coefficient whose (absolute) value is not 0. For example, when the sum of absolute levels for the significant transform coefficients is even, the value of coeff_sign_flag for the first significant transform coefficient can be derived as 1, and when the sum of absolute levels for the significant transform coefficients is odd, the value of coeff_sign_flag for the first significant transform coefficient can be derived as 0. In other words, for example, when the sum of absolute levels for the significant transform coefficients is even, the value of coeff_sign_flag for the first significant transform coefficient can be derived as a negative value, and when the sum of absolute levels for the significant transform coefficients is odd, the value of coeff_sign_flag for the first significant transform coefficient can be derived as a positive value. Or, for example, when the sum of absolute levels for the significant transform coefficients is even, the value of coeff_sign_flag for the first significant transform coefficient can be derived as 0, and when the sum of absolute levels for the significant transform coefficients is odd, the value of coeff_sign_flag for the first significant transform coefficient can be derived as 1. In other words, for example, when the sum of absolute levels for the significant transform coefficients is even, the value of coeff_sign_flag for the first significant transform coefficient can be derived as a positive value, and when the sum of absolute levels for the significant transform coefficients is odd, the value of coeff_sign_flag for the first significant transform coefficient can be derived as a negative value.

[0243] For example, the SDH in residual syntax may be as shown in the following table. [Table 28]

[0244] Referring to Table 8, the signHiddenFlag variable may indicate whether SDH is applied. The signHiddenFlag variable may be referred to as signHidden. For example, when the value of the signHiddenFlag variable is 0, the signHiddenFlag variable may indicate that SDH is not applied, and when the value of the signHiddenFlag variable is 1, the signHiddenFlag variable may indicate that SDH is applied. For example, the value of the signHiddenFlag variable may be set based on the flag information being signed (e.g., sh_sign_data_hiding_used_flag or pic_sign_data_hiding_enabled_flag or sps_sign_data_hiding_enabled_flag). Similarly, for example, the value of the signHiddenFlag variable may be set based on lastSigScanPosSb and firstSigScanPosSb. In this document, lastSigScanPosSb may indicate a position of the last significant transform coefficient searched in the corresponding sub-block/coefficient group according to the scanning order, and firstSigScanPosSb may indicate a position of a first significant transform coefficient searched in a corresponding sub-block/coefficient group according to a scanning order. In general, lastSigScanPosSb may be located in a relatively high frequency component region relative to firstSigScanPosSb. Correspondingly, when lastSigScanPosSb - firstSigScanPosSb is greater than a predetermined threshold, the signHidden value may be derived as 1 (i.e., SDH is applied), otherwise the signHidden value may be derived as 0 (i.e., SDH is not applied). In this document, for example, referring to Table 28, the threshold may be set as 3.

[0245] However, when signal data hiding is enabled in high-level syntax (VPS, SPS, PPS, slice header syntax, etc.) or low-level syntax (slice data syntax, coding unit syntax, transform unit syntax, etc.), and slice_ts_residual_coding_disabled_flag is 1, the RRC signal data hiding process can be used in lossless coding. Correspondingly, lossless coding may become impossible due to incorrect settings in the coding apparatus. Alternatively, when a lossy coding (i.e., an irreversible coding method) other than lossless coding is applied, and a residual signal to which transform omission is applied is coded with RRC and BDPCM is applied at the same time, although the interval where the residual value becomes 0 occurs more frequently than in the general case due to the difference between the residuals in BDPCM, a coding loss may occur because SDH is performed according to the SDH application condition. Specifically, for example, when significant transform coefficients (nonzero residual data) exist at positions 0 and 15 in the CG, respectively, and the value of the transform coefficients at the remaining positions in the CG is 0, SDH may be applied to the CG according to the SDH application condition described above, and therefore, signal data (i.e., coding of a signal flag) for the first significant transform coefficient of the CG may be omitted. Correspondingly, in this case, the parity of only two residual data of the CG can be adjusted in the quantization step to omit the signal data, and instead, in the case where SDH is not applied, more coding loss may occur. This case may occur even in blocks where BDPCM is not applied, but due to the characteristics of BDPCM, the level is lowered through the difference with the neighboring residual, so disadvantageous cases may occur more frequently in applying SDH.

[0246] Therefore, in order to prevent SDH and residual coding of slice_ts_residual_coding_disabled_flag = 1 (i.e., coding residual samples of the transform omission block in the current slice with RRC) from being used to cause unintended coding loss or malfunction, the present disclosure proposes an embodiment for adjusting dependency/constraint between two technologies.

[0247] For example, the present disclosure proposes a method where slice_ts_residual_coding_disabled_flag pic_sign_data_hiding_enabled_flag. The residual coding syntax according to the present embodiment may be as shown in the following table. [Table 29]

[0248] In this document, slice_ts_residual_coding_disabled_flag may be flagged as a slice header syntax, or a High Level Syntax (HLS) other than slice header syntax (e.g., SPS syntax/VPS syntax/DPS syntax, etc.), or low level (CU/TU). Furthermore, pic_sign_data_hiding_enabled_flag may be flagged in figuration header syntax, or another High Level Syntax (HLS) other than figuration header syntax (e.g., SPS syntax/VPS syntax/DPS syntax, etc.), or low level (CU/TU). For example, when pic_sign_data_hiding_enabled_flag is flagged in a syntax other than figuration header syntax, it may be referred to by another name. For example, pic_sign_data_hiding_enabled_flag can be represented by sps_sign_data_hiding_enabled_flag.

[0249] Similarly, sps_sign_data_hiding_enabled_flag may be a flag that indicates whether sign data hiding is enabled. That is, for example, sps_sign_data_hiding_enabled_flag may indicate whether sign data hiding is enabled. For example, when the value of sps_sign_data_hiding_enabled_flag is 1, sps_sign_data_hiding_enabled_flag may indicate that sign data hiding is enabled, and when the value of sps_sign_data_hiding_enabled_flag is 0, sps_sign_data_hiding_enabled_flag may indicate that sign data hiding is not enabled.

[0250] According to Table 29 disclosing the present embodiment, slice_ts_residual_coding_disabled_flag may be flagged only when a signal data hiding is not enabled. Furthermore, when a signal data hiding is enabled, slice_ts_residual_coding_disabled_flag may not be flagged, a value of slice_ts_residual_coding_disabled_flag may be inferred as 0 (encoding the residual sample of the transform omission block in the current slice with TSRC syntax) or 1 (encoding the residual sample of the transform omission block in the current slice with RRC syntax).

[0251] Furthermore, the present disclosure proposes an embodiment where the previously described embodiments are combined with respect to the signaling of sh_ts_residual_coding_disabled_flag. For example, one may propose an embodiment of signaling sh_ts_residual_coding_disabled_flag as shown in the following table. [Table 30]

[0252] Referring to Table 30, when sps_transform_skip_enabled_flag is 1, ph_dep_quant_enabled_flag is 0, and pic_sign_data_hiding_enabled_flag is 0, sh_ts_residual_coding_disabled_disable_flag may be flagged, and otherwise, sh_ts_residual_coding_disabled_disable_flag may not be flagged. Conversely, when sh_ts_residual_coding_disabled_flag is not flagged, sh_ts_residual_coding_disabled_flag may be inferred to be 0.

[0253] However, the embodiment of Table 31 is an example, and one may propose an example where ph_dep_quant_enabled_flag, pic_sign_data_hiding_enabled_flag, and ph_ts_residual_coding_disabled_flag are all flagged in the same HLS (e.g., slice header syntax, etc.).

[0254] Alternatively, for example, one may propose a sh_ts_residual_coding_disabled_flag flagging modality as shown in the following table. [Table 31]

[0255] Referring to Table 31, when ph_dep_quant_enabled_flag is 0 and pic_sign_data_hiding_enabled_flag is 0, sh_ts_residual_coding_disabled_flag may be flagged, and otherwise, sh_ts_residual_coding_disabled_flag may not be flagged. Conversely, when sh_ts_residual_coding_disabled_flag is not flagged, sh_ts_residual_coding_disabled_flag may be inferred to be 0.

[0256] However, the embodiment of Table 31 is an example, and one may propose an example where ph_dep_quant_enabled_flag, pic_sign_data_hiding_enabled_flag, and ph_ts_residual_coding_disabled_flag are all flagged in the same HLS (e.g., slice header syntax, etc.).

[0257] Alternatively, for example, one may propose a sh_ts_residual_coding_disabled_flag flagging modality as shown in the following table. [Table 32]

[0258] Referring to Table 32, when ph_dep_quant_enabled_flag is 0 or pic_sign_data_hiding_enabled_flag is 0, sh_ts_residual_coding_disabled_flag may be flagged, and otherwise, sh_ts_residual_coding_disabled_flag may not be flagged. Conversely, when sh_ts_residual_coding_disabled_flag is not flagged, sh_ts_residual_coding_disabled_flag may be inferred to be 0.

[0259] Furthermore, the present disclosure proposes an embodiment where the syntax elements ph_dep_quant_enabled_flag, pic_sign_data_hiding_enabled_flag and slice_ts_residual_coding_disabled_flag described above are flagged in the same high-level syntax or low-level syntax.

[0260] For example, one may propose an embodiment where ph_dep_quant_enabled_flag, pic_sign_data_hiding_enabled_flag, and slice_ts_residual_coding_disabled_flag are all flagged in the figuration header syntax as shown in the following table. [Table 33]

[0261] In this case, slice_ts_residual_coding_disabled_flag may be referred to as ph_ts_residual_coding_disabled_flag.

[0262] Referring to Table 33, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax, and when a value of ph_ts_residual_coding_disabled_flag is 0, if a value of sps_dep_quant_enabled_flag is 1, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax. Additionally, when the value of ph_ts_residual_coding_disabled_flag is 0, if the value of sps_sign_data_hiding_enabled_flag is 1 and ph_dep_quant_enabled_flag is 0, pic_sign_data_hiding_enabled_flag may be flagged in the figuration header syntax. However, for example, when the value of ph_ts_residual_coding_disabled_flag is 1, ph_dep_quant_enabled_flag and pic_sign_data_hiding_enabled_flag may not be flagged.

[0263] Alternatively, for example, one may propose an embodiment where ph_dep_quant_enabled_flag, pic_sign_data_hiding_enabled_flag, and slice_ts_residual_coding_disabled_flag are all flagged in the figuration header syntax as shown in the following table. [Table 34]

[0264] Referring to Table 34, when the value of sps_transform_skip_enabled_flag is 1, ph_ts_residual_coding_disabled_flag may be flagged in the figuration header syntax. Similarly, for example, when the value of sps_transform_skip_enabled_flag is 0, ph_ts_residual_coding_disabled_flag may not be flagged. When ph_ts_residual_coding_disabled_flag is not flagged, ph_ts_residual_coding_disabled_flag may be inferred to be 0 in the decoding apparatus.

[0265] Similarly, referring to Table 34, when the value of ph_ts_residual_coding_disabled_flag is 0 and the value of sps_dep_quant_enabled_flag is 1, ph_dep_quant_enabled_flag may be flagged in the figuration header syntax. Additionally, when the value of ph_ts_residual_coding_disabled_flag is 0, if the value of sps_sign_data_hiding_enabled_flag is 1 and ph_dep_quant_enabled_flag is 0, pic_sign_data_hiding_enabled_flag may be flagged in the figuration header syntax. However, for example, when the value of ph_ts_residual_coding_disabled_flag is 1, ph_dep_quant_enabled_flag and pic_sign_data_hiding_enabled_flag may not be flagged. Similarly, for example, when ph_dep_quant_enabled_flag is not flagged, ph_dep_quant_enabled_flag may be inferred to be 0 on the decoding machine. Similarly, for example, when pic_sign_data_hiding_enabled_flag is not flagged, pic_sign_data_hiding_enabled_flag may be inferred to be 0 on the decoding machine.

[0266] However, the embodiments described above are examples, one may propose an example where ph_ts_residual_coding_disabled_flag, ph_dep_quant_enabled_flag, and pic_sign_data_hiding_enabled_flag are flagged in a high-level syntax (VPS, SPS, PPS, slice header syntax, etc.) or low-level syntax (slice data syntax, coding unit syntax, etc.) other than the figuration header syntax.

[0267] However, as described above, information (syntax element) in the syntax table disclosed in the present disclosure may be included in the image/video information, and may be configured/encoded in the encoding apparatus and transmitted to the decoding apparatus in the form of a bit stream. The decoding apparatus may analyze/decode information (syntax element) in the corresponding syntax table. The decoding apparatus may perform a block/image/video reconstruction process based on the decoded information.

[0268] Figure 8 briefly illustrates an image encoding method performed by an encoding apparatus in accordance with the present disclosure. The method disclosed in Figure 8 may be performed by the encoding apparatus disclosed in Figure 2. Specifically, for example, S800 through S830 of Figure 8 may be performed by the entropy encoder of the encoding apparatus. Further, although not illustrated, a process of deriving a prediction sample may be performed by the predictor of the encoding apparatus, a process of deriving a residual sample for the current block based on the original sample and the prediction sample for the current block may be performed by the subtractor of the encoding apparatus, and a process of generating a reconstructed sample and a reconstructed picture for the current block based on the residual sample and the prediction sample for the current block may be performed by the adder of the encoding apparatus.

[0269] The encoding apparatus encodes a signal data concealment enabled flag for whether signal data concealment is enabled (S800). The encoding apparatus may encode a signal data concealment enabled flag for whether signal data concealment is enabled. The image information may include the signal data concealment enabled flag. For example, the encoding apparatus may determine whether signal data concealment is enabled for blocks of pictures in a sequence, and may encode the signal data concealment enabled flag for whether signal data concealment is enabled. For example, the signal data concealment enabled flag may be a flag for whether signal data concealment is enabled. For example, the signal data concealment enabled flag may represent whether signal data concealment is enabled. That is, for example, the signal data hiding enabled flag may represent whether signal data hiding is enabled for blocks of figures in a sequence. For example, the signal data hiding enabled flag may represent whether a signal data hiding used flag may be present. For example, the signal data hiding enabled flag having a value of 1 may represent that signal data hiding is enabled, and the signal data hiding enabled flag having a value of 0 may represent that signal data hiding is not enabled. For example, the signal data hiding enabled flag having a value of 1 may represent that signal data hiding used a flag may be present, and the signal data hiding enabled flag having a value of 0 may represent that signal data hiding used a flag is not present. Similarly, for example, the sign data hiding enabled flag can be flagged in an SPS syntax. Alternatively, for example, the sign data hiding enabled flag can be flagged in a figuration header syntax or a slice header syntax. The syntax element for the sign data hiding enabled flag can be sps_sign_data_hiding_enabled_flag.

[0270] The encoding apparatus encodes a transform omission residual coding (TSRC) enabled flag for whether TSRC is enabled based on the signal data concealment enabled flag (S810). The picture information may include the TSRC enabled flag.

[0271] For example, the encoding apparatus may encode the TSRC-enabled flag based on the signal data concealment-enabled flag. For example, the TSRC-enabled flag may be encoded based on the signal data concealment-enabled flag having a value of 0. That is, for example, when a value of the signal data concealment-enabled flag is 0 (i.e., the signal data concealment-enabled flag represents that signal data concealment is not enabled), the TSRC-enabled flag may be encoded. In other words, for example, when a value of the signal data concealment-enabled flag is 0 (i.e., the signal data concealment-enabled flag represents that signal data concealment is not enabled), the TSRC-enabled flag may be signaled. Similarly, for example, when the value of the signal data concealment enabled flag is 1, the TSRC enabled flag may not be encoded, and a value of the TSRC enabled flag may be derived as 0 in the decoding apparatus. That is, for example, when the value of the signal data concealment enabled flag is 1, the TSRC enabled flag may not be signaled, and a value of the TSRC enabled flag may be derived as 0 in the decoding apparatus.

[0272] In this document, for example, the TSRC-enabled flag may be a flag for whether TSRC is enabled. That is, for example, the TSRC-enabled flag may be a flag that represents whether TSRC is enabled for blocks in a slice. For example, the TSRC-enabled flag having a value of 1 may represent that TSRC is not enabled, and the TSRC-enabled flag having a value of 0 may represent that TSRC is enabled. Likewise, for example, the TSRC-enabled flag may be flagged in a slice header syntax. The TSRC-enabled flag syntax element may be sh_ts_residual_coding_disabled_flag described previously.

[0273] However, for example, the encoding apparatus may determine whether dependent quantization is enabled for blocks of pictures in a sequence, and may encode the dependent quantization enabled flag for whether dependent quantization is enabled. The picture information may include the dependent quantization enabled flag. For example, the dependent quantization enabled flag may be a flag for whether dependent quantization is enabled. For example, the dependent quantization enabled flag may represent whether dependent quantization is enabled. That is, for example, the dependent quantization enabled flag may represent whether dependent quantization is enabled for blocks of pictures in a sequence. For example, the dependent quantization enabled flag may represent whether dependent quantization has been used; a flag representing whether dependent quantization is used for a current slice may be present. For example, the dependent quantization-enabled flag having a value of 1 might represent that dependent quantization is enabled, and the dependent quantization-enabled flag having a value of 0 might represent that dependent quantization is not enabled. Similarly, for example, the dependent quantization-enabled flag might be flagged in an SPS syntax or a slice header syntax. The dependent quantization-enabled flag syntax element might be sps_dep_quant_enabled_flag described earlier. sps_dep_quant_enabled_flag might be referred to as sh_dep_quant_enabled_flag, sh_dep_quant_used_flag, or ph_dep_quant_enabled_flag.

[0274] Further, for example, the encoding apparatus may encode the transform omit enabled flag for whether transform omit is enabled. Picture information may include the transform omit enabled flag. For example, the encoding apparatus may determine whether transform omit is enabled for blocks of pictures in a sequence, and may encode the transform omit enabled flag for whether transform omit is enabled. For example, the transform omit enabled flag may be a flag for whether transform omit is enabled. For example, the transform omit enabled flag may represent whether transform omit is enabled. That is, for example, the transform omit enabled flag may represent whether transform omit is enabled for blocks of pictures in the sequence. For example, the transform omit enabled flag may represent whether the transform omit flag may be present. For example, the transform-skip-enabled flag having a value of 1 can represent that transform skipping is enabled, and the transform-skip-enabled flag having a value of 0 can represent that transform skipping is not enabled. That is, for example, the transform-skip-enabled flag having a value of 1 can represent that the transform-skip flag can be present, and the transform-skip-enabled flag having a value of 0 can represent that the transform-skip-enabled flag is not present. Furthermore, for example, the transform-skip-enabled flag can be flagged to a sequence parameter set (SPS) syntax. The syntax element for the transform-skip-enabled flag can be sps_transform_skip_enabled_flag described previously.

[0275] Further, for example, the TSRC-enabled flag may be encoded based on the signal data hiding-enabled flag, the dependent quantization-enabled flag, and/or the transform omission-enabled flag. For example, the TSRC-enabled flag may be encoded based on the signal data hiding-enabled flag having a value of 0, the dependent quantization-enabled flag having a value of 0, and the transform omission-enabled flag having a value of 1. That is, for example, when a value of the signal data hiding-enabled flag is 0 (i.e., the signal data hiding-enabled flag represents that a signal data hiding is not enabled), a value of the dependent quantization-enabled flag is 0 (i.e., the dependent quantization-enabled flag represents that a dependent quantization is not enabled), and a value of the transform omission-enabled flag is 1 (i.e., the transform omission-enabled flag represents that a transform omission is enabled), the TSRC-enabled flag may be encoded (or flagged). Similarly, for example, when the value of the dependent quantization-enabled flag is 1, the TSRC-enabled flag may not be encoded, and the TSRC-enabled flag value may be derived as 0 in the decoding apparatus. That is, for example, when the value of the dependent quantization-enabled flag is 1, the TSRC-enabled flag may not be signaled, and the TSRC-enabled flag value may be derived as 0 in the decoding apparatus. Similarly, for example, when the value of the transform-skip-enabled flag is 0, the TSRC-enabled flag may not be encoded, and the TSRC-enabled flag value may be derived as 0. That is, for example, when the value of the transform-skip-enabled flag is 0, the TSRC-enabled flag may not be signaled, and the TSRC-enabled flag value may be derived as 0.

[0276] The encoding apparatus encodes residual information for a current block based on the TSRC enabled flag (S820). The encoding apparatus may encode residual information for a current block based on the TSRC enabled flag.

[0277] For example, the encoding apparatus may determine a residual encoding syntax for the current block based on the TSRC-enabled flag. For example, the encoding apparatus may determine the residual encoding syntax for the current block as one of a regular residual encoding (RRC) syntax and a transform omission residual encoding (TSRC) syntax based on the TSRC-enabled flag. The RRC syntax may represent a syntax in accordance with RRC, and the TSRC syntax may represent a syntax in accordance with TSRC.

[0278] For example, based on the TSRC-enabled flag having the value of 1, the residual coding syntax for the current block may be determined as the regular residual coding (RRC) syntax. In this case, for example, the transform skip flag for whether the current block is the transform skip block may be encoded, and the transform skip flag value may be 1. For example, the image information may include the transform skip flag for the current block. The transform skip flag may represent whether the current block is the transform skip block. That is, the transform skip flag may represent whether the transform has been applied to the transform coefficients of the current block. The syntax element representing the transform skip flag may be transform_skip_flag as previously described. For example, if the transform omit flag value is 1, the transform omit flag may represent that the transform has not been applied to the current block (i.e., transform omit), whereas if the transform omit flag value is 0, the transform omit flag may represent that the transform has been applied to the current block. For example, if the current block is the transform omit block, the transform omit flag value for the current block may be 1.

[0279] Further, for example, based on the TSRC-enabled flag having the value of 0, the residual coding syntax for the current block may be determined as the transform omission residual coding (TSRC) syntax. Further, for example, the transform omission flag for whether the current block is the transform omission block may be encoded, and based on the transform omission flag having the value of 1 and the TSRC-enabled flag having the value of 0, the residual coding syntax for the current block may be determined as the transform omission residual coding (TSRC) syntax. Furthermore, for example, the transform omit flag for whether the current block is the transform omit block can be encoded, and based on the transform omit flag having the value of 0 and the TSRC enabled flag having the value of 0, the residual coding syntax for the current block can be determined as the regular residual coding (RRC) syntax.

[0280] Subsequently, for example, the encoding apparatus may encode residual information of the residual coding syntax determined for the current block. The encoding apparatus may derive a residual sample for the current block, and may encode residual information of the residual coding syntax determined for the residual sample of the current block. For example, residual information of the regular residual coding (RRC) syntax may be encoded based on the TSRC-enabled flag having the value of 1, and residual information of the TSRC syntax may be encoded based on the TSRC-enabled flag having the value of 0. The picture information may include the residual information.

[0281] For example, the encoding apparatus may determine whether to perform interprediction or intraprediction on the current block, and may determine a specific interprediction mode or intraprediction mode based on the RD cost. According to the determined mode, the encoding apparatus may derive prediction samples for the current block, and may derive residual samples for the current block by subtracting the prediction samples from the original samples for the current block.

[0282] Thus, for example, the coding apparatus may derive the transform coefficients of the current block based on the residual samples. For example, the coding apparatus may determine whether the transform is applied to the current block. That is, the coding apparatus may determine whether the transform is applied to the residual samples of the current block. The coding apparatus may determine whether the transform is applied to the current block in consideration of coding efficiency. For example, the coding apparatus may determine that the transform is not applied to the current block. The block to which the transform is not applied may be represented as the transform-skipping block. That is, for example, the current block may be the transform-skipping block.

[0283] If the transform is not applied to the current block, i.e., if the transform is not applied to the residual samples, the coding apparatus may derive the derived residual samples as the current transform coefficients. Further, if the transform is applied to the current block, i.e., if the transform is applied to the residual samples, the coding apparatus may derive the transform coefficients by performing the transform to the residual samples. The current block may include a plurality of sub-blocks or coefficient groups (CGs). Further, the sub-block size of the current block may be 4x4 or 2x2. That is, the sub-block of the current block may maximally include 16 non-zero transform coefficients or 4 non-zero transform coefficients. In this document, the current block may be the coding block (CB) or the transform block (TB). Further, the transform coefficient may be represented as the residual coefficient.

[0284] However, the encoding apparatus may determine whether dependent quantization is applied for the current block. For example, if dependent quantization is applied for the current block, the encoding apparatus may derive the transform coefficients of the current block by performing the dependent quantization process for the transform coefficients. For example, if dependent quantization is applied for the current block, the encoding apparatus may update the state (Qstate) for dependent quantization based on the coefficient level of the transform coefficient just before the current transform coefficient in the scan order, may derive the coefficient level of the current transform coefficient based on the updated state and the syntax elements for the current transform coefficient, and may derive the current transform coefficient by quantizing the derived coefficient level. For example, the current transform coefficient may be quantized based on the quantization parameter for the reconstructed level of the current transform coefficient in a scalar quantizer for the updated state.

[0285] For example, if the residual coding syntax for the current block is determined to be RRC syntax, the encoding apparatus may encode the residual RRC syntax information for the current block. For example, the residual RRC syntax information may include the syntax elements disclosed in Table 2 as described above.

[0286] For example, the residual RRC syntax information may include the syntax elements for the transform coefficient of the current block. In this document, the transform coefficient may be represented as the residual coefficient.

[0287] For example, syntax elements may include syntax elements such as last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, last_sig_coeff_y_suffix, sb_coded_flag, sig_coeff_flag, par_level_flag, abs_level_gtX_flag (e.g., abs_level_gtx_flag[n][0] and/or abs_level_gtx_flag[n][1]), abs_remainder, dec_abs_level, and/or coeff_sign_flag.

[0288] Specifically, for example, the syntax elements may include position information representing the position of the last non-zero transform coefficient in a residual coefficient array of the current block. That is, the syntax elements may include position information representing the position of the last non-zero transform coefficient in the scan order of the current block. The position information may include information representing a prefix at a column position of the last non-zero transform coefficient, information representing a prefix at a row position of the last non-zero transform coefficient, information representing a suffix at the column position of the last non-zero transform coefficient, and information representing a suffix at the row position of the last non-zero transform coefficient. The syntax elements for the position information may be last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, and last_sig_coeff_y_suffix. However, the nonzero transform coefficient can be termed as a significant coefficient.

[0289] Further, for example, the syntax elements may include a coded subblock flag representing whether the current subblock of the current block includes the non-zero transform coefficient, a significant coefficient flag representing whether the transform coefficient of the current block is the non-zero transform coefficient, a first coefficient level flag for whether the coefficient level for the transform coefficient is greater than a first threshold value, a parity level flag for a parity of the coefficient level, and/or a second coefficient level flag for whether the coefficient level of the transform coefficient is greater than a second threshold value. In this document, the coded sub-block flag may be sb_coded_flag or coded_sub_block_flag, the significant coefficient flag may be sig_coeff_flag, the first coefficient level flag may be abs_level_gt1_flag or abs_level_gtx_flag, the parity level flag may be par_level_flag, and the second coefficient level flag may be abs_level_gt3_flag or abs_level_gtx_flag.

[0290] Further, for example, the syntax elements may include coefficient value related information for the transform coefficient value of the current block. The coefficient value related information may be abs_remainder and/or dec_abs_level.

[0291] Further, for example, the syntax elements may include a sign flag that represents the sign of the transform coefficient. The sign flag may be coeff_sign_flag.

[0292] However, for example, when signal data hiding is applied to the current block, a signal flag of a first significant transform coefficient of a current coefficient group (CG) in the current block may not be encoded and signaled. That is, for example, when signal data hiding is applied to the current block, the syntax elements may not include a signal flag representing a signal of the first significant transform coefficient. However, for example, whether signal data hiding is applied to the current block may be derived based on the signal data hiding enabled flag and/or a position of the first significant transform coefficient and a position of the last significant transform coefficient of the current CG. For example, when a value of the signal data hiding enabled flag is 1, and a value obtained by subtracting the position of the first significant transform coefficient from the position of the last significant transform coefficient is greater than 3, (i.e., when a value of the signal data hiding enabled flag is 1, and a number of significant transform coefficients in the current CG is greater than 3), signal data hiding may be applied to the current CG of the current block.

[0293] Further, for example, if the residual encoding syntax for the current block is determined to be the TSRC syntax, the encoding apparatus may encode the residual TSRC syntax information for the current block. For example, the residual TSRC syntax information may include the syntax elements disclosed in Table 3 as described above.

[0294] For example, the residual TSRC syntax information may include the syntax elements for the transform coefficient of the current block. In this document, the transform coefficient may be represented as the residual coefficient.

[0295] For example, the syntax elements may include context-encoded syntax elements for the transform coefficient and/or bias-encoded syntax elements. The syntax elements may include syntax elements such as sig_coeff_flag, coeff_sign_flag, par_level_flag, abs_level_gtX_flag (e.g., abs_level_gtx_flag[n][0], abs_level_gtx_flag[n][1], abs_level_gtx_flag[n][2], abs_level_gtx_flag[n][3], and/or abs_level_gtx_flag[n][4]), abs_remainder, and/or coeff_sign_flag.

[0296] For example, the context-encoded syntax elements for the transform coefficient may include a significant coefficient flag representing whether the transform coefficient is the nonzero transform coefficient, a sign flag representing the sign for the transform coefficient, a first coefficient level flag for whether the coefficient level for the transform coefficient is greater than a first threshold value, and/or a parity level flag for the parity of the transform level for the transform coefficient. Further, for example, the context-encoded syntax elements may include a second coefficient level flag for whether the coefficient level of the transform coefficient is greater than a second threshold value, a third coefficient level flag for whether the coefficient level of the transform coefficient is greater than a third threshold value, a fourth coefficient level flag for whether the coefficient level of the transform coefficient is greater than a fourth threshold value, and/or a fifth coefficient level flag for whether the coefficient level of the transform coefficient is greater than a fifth threshold value. In this document, the significant coefficient flag may be sig_coeff_flag, the sign flag may be ceff_sign_flag, the first coefficient level flag may be abs_level_gt1_flag, and the parity level flag may be par_level_flag. Furthermore, the second coefficient level flag can be abs_level_gt3_flag or abs_level_gtx_flag, the third coefficient level flag can be abs_level_gt5_flag or abs_level_gtx_flag, the fourth coefficient level flag can be abs_level_gt7_flag or abs_level_gtx_flag, and the fifth coefficient level flag can be abs_level_gt9_flag or abs_level_gtx_flag.

[0297] Further, for example, the offset-encoded syntax elements for the transform coefficient may include coefficient level information for the transform coefficient value (or coefficient level) and/or a sign flag representing the sign for the transform coefficient. The coefficient level information may be abs_remainder and/or dec_abs_level, and the sign flag may be ceff_sign_flag.

[0298] The encoding apparatus generates a bit stream including the signal data hiding enabled flag, the TSRC enabled flag, and the residual information (S830). For example, the encoding apparatus may output picture information including the signal data hiding enabled flag, the TSRC enabled flag, and the residual information as the bit stream. The bit stream may include the signal data hiding enabled flag, the TSRC enabled flag, and the residual information. Likewise, the bit stream may further include the dependent quantization enabled flag and/or the transform omission enabled flag.

[0299] However, the image information may include prediction-related information for the current block. The prediction-related information may include prediction mode information for an inter-prediction mode or an intra-prediction mode performed on the current block.

[0300] However, the bit stream may be transmitted to the set-top box via a network or a (digital) storage medium. In this document, the network may include a broadcasting network and/or a communication network, and the digital storage medium may include various storage media, such as USB, SD, CD, DVD, Blu-ray, HDD, and SSD.

[0301] Figure 9 briefly illustrates a coding apparatus for performing an image coding method in accordance with the present disclosure. The method disclosed in Figure 8 may be performed by the coding apparatus disclosed in Figure 9. Specifically, for example, the entropy encoder of the coding apparatus of Figure 9 may perform S800 through S830 of Figure 8. Further, although not illustrated, a process of deriving a prediction sample may be performed by the predictor of the coding apparatus, a process of deriving a residual sample for the current block based on the original sample and the prediction sample for the current block may be performed by the subtractor of the coding apparatus, and a process of generating a reconstructed sample and a reconstructed picture for the current block based on the residual sample and the prediction sample for the current block may be performed by the adder of the coding apparatus.

[0302] Figure 10 briefly illustrates a picture decoding method performed by a decoding apparatus in accordance with the present disclosure. The method disclosed in Figure 10 may be performed by the decoding apparatus disclosed in Figure 3. Specifically, for example, S1000 through S1020 of Figure 10 may be performed by the entropy decoder of the decoding apparatus, S1030 of Figure 10 may be performed by the residual processor of the decoding apparatus, and S1040 may be performed by the adder of the decoding apparatus. Furthermore, although not illustrated, a process of receiving prediction information for the current block may be performed by the entropy decoder of the decoding apparatus, and a process of deriving a prediction sample from the current block may be performed by the predictor of the decoding apparatus.

[0303] The decoding apparatus obtains a signal data hiding enabled flag (S1000). The decoding apparatus may obtain picture information including the signal data hiding enabled flag via a bit stream. The picture information may include the signal data hiding enabled flag. For example, the signal data hiding enabled flag may be a flag for whether signal data hiding is enabled. For example, the signal data hiding enabled flag may represent whether signal data hiding is enabled. That is, for example, the signal data hiding enabled flag may represent whether signal data hiding is enabled for blocks of pictures in a sequence. For example, the signal data hiding enabled flag may represent whether a signal data hiding has been used for a current slice. A flag representing whether signal data hiding is used for a current slice may be present. For example, the signal data hiding enabled flag having a value of 1 may represent that signal data hiding is enabled, and the signal data hiding enabled flag having a value of 0 may represent that signal data hiding is not enabled. For example, the signal data hiding enabled flag having a value of 1 may represent that signal data hiding used a flag may be present, and the signal data hiding enabled flag having a value of 0 may represent that signal data hiding used a flag may not be present. Similarly, for example, the signal data hiding enabled flag may be flagged in an SPS syntax. Alternatively, for example, the signal data hiding enabled flag may be flagged in a figuration header syntax or a slice header syntax. The syntax element for the signal data hiding enabled flag may be sps_sign_data_hiding_enabled_flag.

[0304] The decoding apparatus obtains a transform omission residual coding (TSRC) enabled flag based on the signal data hiding enabled flag (S1010). The picture information may include the TSRC enabled flag.

[0305] For example, the decoding apparatus may obtain the TSRC-enabled flag based on the signal data concealment-enabled flag. For example, the TSRC-enabled flag may be obtained based on the signal data concealment-enabled flag having a value of 0. That is, for example, when a value of the signal data concealment-enabled flag is 0 (i.e., the signal data concealment-enabled flag represents that signal data concealment is not enabled), the TSRC-enabled flag may be obtained. In other words, for example, when a value of the signal data concealment-enabled flag is 0 (i.e., the signal data concealment-enabled flag represents that signal data concealment is not enabled), the TSRC-enabled flag may be signaled. Similarly, for example, when the value of the signal data hiding enabled flag is 1, the TSRC enabled flag may not be obtained, and a value of the TSRC enabled flag may be derived as 0. That is, for example, when the value of the signal data hiding enabled flag is 1, the TSRC enabled flag may not be signaled, and a value of the TSRC enabled flag may be derived as 0.

[0306] In this document, for example, the TSRC-enabled flag may be a flag for whether TSRC is enabled. That is, for example, the TSRC-enabled flag may be a flag that represents whether TSRC is enabled for blocks in a slice. For example, the TSRC-enabled flag having a value of 1 may represent that TSRC is not enabled, and the TSRC-enabled flag having a value of 0 may represent that TSRC is enabled. Likewise, for example, the TSRC-enabled flag may be flagged in a slice header syntax. The TSRC-enabled flag syntax element may be sh_ts_residual_coding_disabled_flag described previously.

[0307] However, for example, the decoding apparatus may obtain a dependent quantization enabled flag. The decoding apparatus may obtain picture information including the dependent quantization enabled flag via a bit stream. The picture information may include the dependent quantization enabled flag. For example, the dependent quantization enabled flag may be a flag for whether dependent quantization is enabled. For example, the dependent quantization enabled flag may represent whether dependent quantization is enabled. That is, for example, the dependent quantization enabled flag may represent whether dependent quantization is enabled for blocks of pictures in a sequence. For example, the dependent quantization enabled flag may represent whether dependent quantization has been used for a current slice. A flag representing whether dependent quantization is used for a current slice may be present. For example, the dependent quantization-enabled flag having a value of 1 might represent that dependent quantization is enabled, and the dependent quantization-enabled flag having a value of 0 might represent that dependent quantization is not enabled. Similarly, for example, the dependent quantization-enabled flag might be flagged in an SPS syntax or a slice header syntax. The dependent quantization-enabled flag syntax element might be sps_dep_quant_enabled_flag described earlier. sps_dep_quant_enabled_flag might be referred to as sh_dep_quant_enabled_flag, sh_dep_quant_used_flag, or ph_dep_quant_enabled_flag.

[0308] Further, for example, the decoding apparatus may obtain a transform omit enabled flag. The decoding apparatus may pass picture information including the transform omit enabled flag through the bit stream. Picture information may include the transform omit enabled flag. In this document, the current block may be a coding block (CB) or a transform block (TB). For example, the transform omit enabled flag may be a flag for whether transform omit is enabled. For example, the transform omit enabled flag may represent whether transform omit is enabled. That is, for example, the transform omit enabled flag may represent whether transform omit is enabled for blocks of the pictures in the sequence. For example, the transform omit enabled flag may represent whether the transform omit flag may be present. For example, the transform-skip-enabled flag having a value of 1 can represent that transform skipping is enabled, and the transform-skip-enabled flag having a value of 0 can represent that transform skipping is not enabled. That is, for example, the transform-skip-enabled flag having a value of 1 can represent that the transform-skip flag can be present, and the transform-skip-enabled flag having a value of 0 can represent that the transform-skip-enabled flag is not present. Furthermore, for example, the transform-skip-enabled flag can be flagged to a sequence parameter set (SPS) syntax. The syntax element for the transform-skip-enabled flag can be sps_transform_skip_enabled_flag described previously.

[0309] Further, for example, the TSRC-enabled flag may be obtained based on the signal data hiding-enabled flag, the dependent quantization-enabled flag, and/or the transform omission-enabled flag. For example, the TSRC-enabled flag can be obtained based on the signal data hiding-enabled flag having a value of 0, the dependent quantization-enabled flag having a value of 0, and the transform omission-enabled flag having a value of 1. That is, for example, when a value of the signal data hiding-enabled flag is 0 (i.e., the signal data hiding-enabled flag represents that a signal data hiding is not enabled), a value of the dependent quantization-enabled flag is 0 (i.e., the dependent quantization-enabled flag represents that a dependent quantization is not enabled), and a value of the transform omission-enabled flag is 1 (i.e., the transform omission-enabled flag represents that a transform omission is enabled), the TSRC-enabled flag can be obtained (or flagged). Similarly, for example, when the value of the dependent quantization-enabled flag is 1, the TSRC-enabled flag may not be obtained, and the TSRC-enabled flag value may be derived as 0. That is, for example, when the value of the dependent quantization-enabled flag is 1, the TSRC-enabled flag may not be signaled, and the TSRC-enabled flag value may be derived as 0. Similarly, for example, when the value of the transform-skip-enabled flag is 0, the TSRC-enabled flag may not be obtained, and the TSRC-enabled flag value may be derived as 0. That is, for example, when the value of the transform-skip-enabled flag is 0, the TSRC-enabled flag may not be signaled, and the TSRC-enabled flag value may be derived as 0.

[0310] The decoding apparatus obtains residual information for a current block based on the TSRC enabled flag (S1020). Decoding may obtain residual information for a current block based on the TSRC enabled flag.

[0311] For example, the decoding apparatus may determine a residual coding syntax for the current block based on the TSRC-enabled flag. For example, the decoding apparatus may determine the residual coding syntax for the current block as one of a regular residual coding (RRC) syntax and a transform omission residual coding (TSRC) syntax based on the TSRC-enabled flag. The RRC syntax may represent a syntax in accordance with RRC, and the TSRC syntax may represent a syntax in accordance with TSRC.

[0312] For example, based on the TSRC enabled flag having a value of 1, the residual coding syntax for the current block may be determined as the regular residual coding (RRC) syntax. In this case, for example, a transform skip flag for whether transform skip is applied to the current block may be obtained based on the transform skip enabled flag having a value of 1, and the transform skip flag value may be 1. For example, the image information may include the transform skip flag for the current block. The transform skip flag may represent whether the current block is the transform skip block. That is, the transform skip flag may represent whether the transform has been applied to the transform coefficients of the current block. The syntax element representing the transform skip flag may be transform_skip_flag as previously described. For example, if the transform omit flag value is 1, the transform omit flag may represent that the transform has not been applied to the current block (i.e., transform omit), whereas if the transform omit flag value is 0, the transform omit flag may represent that the transform has been applied to the current block. For example, if the current block is the transform omit block, the transform omit flag value for the current block may be 1.

[0313] Further, for example, based on the TSRC-enabled flag having the value of 0, the residual coding syntax for the current block may be determined as the transform omission residual coding (TSRC) syntax. Further, for example, the transform omission flag for whether a transform omission is applied to the current block may be obtained, and based on the transform omission flag having the value of 1 and the TSRC-enabled flag having the value of 0, the residual coding syntax for the current block may be determined as the transform omission residual coding (TSRC) syntax. Further, for example, the transform omit flag for whether a transform omit is applied to the current block can be obtained, and based on the transform omit flag having the value of 0 and the TSRC enabled flag having the value of 0, the residual coding syntax for the current block can be determined as the regular residual coding (RRC) syntax.

[0314] Subsequently, for example, the decoding apparatus may obtain residual information of the residual coding syntax determined for the current block. For example, residual information of the regular residual coding (RRC) syntax may be obtained based on the TSRC-enabled flag having the value of 1, and residual information of the TSRC syntax may be obtained based on the TSRC-enabled flag having the value of 0. The picture information may include the residual information.

[0315] For example, if the residual coding syntax for the current block is determined to be RRC syntax, the decoding apparatus may obtain the residual RRC syntax information for the current block. For example, the residual RRC syntax information may include the syntax elements disclosed in Table 2 as described above.

[0316] For example, the residual RRC syntax information may include the syntax elements for the transform coefficient of the current block. In this document, the transform coefficient may be represented as the residual coefficient.

[0317] For example, syntax elements may include syntax elements such as last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, last_sig_coeff_y_suffix, sb_coded_flag, sig_coeff_flag, par_level_flag, abs_level_gtX_flag (e.g., abs_level_gtx_flag[n][0] and/or abs_level_gtx_flag[n][1]), abs_remainder, dec_abs_level, and/or coeff_sign_flag.

[0318] Specifically, for example, the syntax elements may include position information representing the position of the last non-zero transform coefficient in an array of residual coefficients of the current block. That is, the syntax elements may include position information representing the position of the last non-zero transform coefficient in the scan order of the current block. The position information may include information representing a prefix at a column position of the last non-zero transform coefficient, information representing a prefix at a row position of the last non-zero transform coefficient, information representing a suffix at the column position of the last non-zero transform coefficient, and information representing a suffix at the row position of the last non-zero transform coefficient. The syntax elements for the position information may be last_sig_coeff_x_prefix, last_sig_coeff_y_prefix, last_sig_coeff_x_suffix, and last_sig_coeff_y_suffix. However, the nonzero transform coefficient can be termed as a significant coefficient.

[0319] Further, for example, the syntax elements may include a coded subblock flag representing whether the current subblock of the current block includes the non-zero transform coefficient, a significant coefficient flag representing whether the transform coefficient of the current block is the non-zero transform coefficient, a first coefficient level flag for whether the coefficient level for the transform coefficient is greater than a first threshold value, a parity level flag for a parity of the coefficient level, and/or a second coefficient level flag for whether the coefficient level of the transform coefficient is greater than a second threshold value. In this document, the coded sub-block flag may be sb_coded_flag or coded_sub_block_flag, the significant coefficient flag may be sig_coeff_flag, the first coefficient level flag may be abs_level_gt1_flag or abs_level_gtx_flag, the parity level flag may be par_level_flag, and the second coefficient level flag may be abs_level_gt3_flag or abs_level_gtx_flag.

[0320] Further, for example, the syntax elements may include coefficient value related information for the transform coefficient value of the current block. The coefficient value related information may be abs_remainder and/or dec_abs_level.

[0321] Further, for example, the syntax elements may include a sign flag that represents the sign of the transform coefficient. The sign flag may be coeff_sign_flag.

[0322] However, for example, when signal data hiding is applied to the current block, a signal flag of a first significant transform coefficient of a current coefficient group (CG) in the current block may not be signaled. That is, for example, when signal data hiding is applied to the current block, the syntax elements may not include a signal flag representing a signal of the first significant transform coefficient. However, for example, whether signal data hiding is applied to the current block may be derived based on the signal data hiding enabled flag and/or a position of the first significant transform coefficient and a position of the last significant transform coefficient of the current CG. For example, when a value of the signal data hiding enabled flag is 1, and a value obtained by subtracting the position of the first significant transform coefficient from the position of the last significant transform coefficient is greater than 3, (i.e., when a value of the signal data hiding enabled flag is 1, and a number of significant transform coefficients in the current CG is greater than 3), signal data hiding may be applied to the current CG of the current block.

[0323] Further, for example, if the residual coding syntax for the current block is determined to be the TSRC syntax, the decoding apparatus may obtain the residual TSRC syntax information for the current block. For example, the residual TSRC syntax information may include the syntax elements disclosed in Table 3 as described above.

[0324] For example, the residual TSRC syntax information may include the syntax elements for the transform coefficient of the current block. In this document, the transform coefficient may be represented as the residual coefficient.

[0325] For example, the syntax elements may include context-encoded syntax elements for the transform coefficient and/or bias-encoded syntax elements. The syntax elements may include syntax elements such as sig_coeff_flag, coeff_sign_flag, par_level_flag, abs_level_gtX_flag (e.g., abs_level_gtx_flag[n][0], abs_level_gtx_flag[n][1], abs_level_gtx_flag[n][2], abs_level_gtx_flag[n][3], and/or abs_level_gtx_flag[n][4]), abs_remainder, and/or coeff_sign_flag.

[0326] For example, the context-encoded syntax elements for the transform coefficient may include a significant coefficient flag representing whether the transform coefficient is the nonzero transform coefficient, a sign flag representing the sign for the transform coefficient, a first coefficient level flag for whether the coefficient level for the transform coefficient is greater than a first threshold value, and/or a parity level flag for the parity of the transform level for the transform coefficient. Further, for example, the context-encoded syntax elements may include a second coefficient level flag for whether the coefficient level of the transform coefficient is greater than a second threshold value, a third coefficient level flag for whether the coefficient level of the transform coefficient is greater than a third threshold value, a fourth coefficient level flag for whether the coefficient level of the transform coefficient is greater than a fourth threshold value, and/or a fifth coefficient level flag for whether the coefficient level of the transform coefficient is greater than a fifth threshold value. In this document, the significant coefficient flag may be sig_coeff_flag, the sign flag may be ceff_sign_flag, the first coefficient level flag may be abs_level_gt1_flag, and the parity level flag may be par_level_flag. Furthermore, the second coefficient level flag can be abs_level_gt3_flag or abs_level_gtx_flag, the third coefficient level flag can be abs_level_gt5_flag or abs_level_gtx_flag, the fourth coefficient level flag can be abs_level_gt7_flag or abs_level_gtx_flag, and the fifth coefficient level flag can be abs_level_gt9_flag or abs_level_gtx_flag.

[0327] Further, for example, the offset-encoded syntax elements for the transform coefficient may include coefficient level information for the transform coefficient value (or coefficient level) and/or a sign flag representing the sign for the transform coefficient. The coefficient level information may be abs_remainder and/or dec_abs_level, and the sign flag may be ceff_sign_flag.

[0328] The decoding apparatus derives a residual sample of the current block based on the residual information (S1030). For example, the decoding apparatus may derive transform coefficients of the current block based on the residual information, and may derive residual samples of the current block based on the transform coefficients.

[0329] For example, the decoding apparatus may derive the transform coefficients of the current block based on the syntax elements of the residual information. Subsequently, the decoding apparatus may derive the residual samples of the current block based on the transform coefficients. As an example, if it is derived that the transform is not applied for the current block based on the transform omit flag, i.e., if the value of the transform omit flag is 1, the decoding apparatus may derive the transform coefficients as the residual samples of the current block. Further, for example, if it is derived that the transform is not applied for the current block based on the transform omit flag, i.e., if the value of the transform omit flag is 1, the decoding apparatus may derive the residual samples of the current block by dequantizing the transform coefficients. Further, for example, if it is derived that the transform is applied to the current block based on the transform omit flag, i.e., if the value of the transform omit flag is 0, the decoding apparatus may derive the residual samples of the current block by performing an inverse transform of the transform coefficients. Further, for example, if it is derived that the transform is applied to the current block based on the transform omit flag, i.e., if the value of the transform omit flag is 0, the decoding apparatus may derive the residual samples of the current block by dequantizing the transform coefficients and performing an inverse transform of the dequantized transform coefficients.

[0330] However, in the case where dependent quantization is applied to the current block, the decoding apparatus may derive the residual samples of the current block by performing the dependent quantization process for the transform coefficients. For example, in the case where dependent quantization is applied to the current block, the decoding apparatus may update the state (Qstate) for dependent quantization based on the coefficient level of the transform coefficient just before the current transform coefficient in the scan order, may derive the coefficient level of the current transform coefficient based on the updated state and the syntax elements for the current transform coefficient, and may derive the residual sample by dequantizing the derived coefficient level. For example, the current transform coefficient may be dequantized based on the quantization parameter for a reconstructed level of the current transform coefficient in a scalar quantizer for the updated state. In the present document, the reconstructed level may be derived based on the syntax elements for the current transform coefficient.

[0331] However, for example, when signal data hiding is applied to the current block, a sign of a first significant transform coefficient of the current CG in the current block may be derived based on the sum of absolute values of significant transform coefficients in the current CG. For example, when the sum of the absolute values of the significant transform coefficients is even, the sign of the first significant transform coefficient may be derived as a positive value, and when the sum of the absolute values of the significant transform coefficients is odd, the sign of the first significant transform coefficient may be derived as a negative value.

[0332] The decoding apparatus generates a reconstructed pattern based on the residual sample (S1040). For example, the decoding apparatus may generate the reconstructed sample and/or reconstructed pattern of the current block based on the residual sample. For example, the decoding apparatus may derive a prediction sample by performing an inter-prediction mode or an intra-prediction mode on the current block based on the prediction information received through the bit stream, and may generate the reconstructed sample by adding the prediction sample and the residual sample to each other.

[0333] Subsequently, as needed, in order to improve the amount of subjective/objective figuration, a loop filtering procedure, such as deblocking filtering, SAO and/or ALF procedure, can be applied to the reconstructed figuration as described above.

[0334] Figure 11 briefly illustrates a decoding apparatus for performing a picture decoding method in accordance with the present disclosure. The method disclosed in Figure 10 may be performed by the decoding apparatus disclosed in Figure 11. Specifically, for example, the entropy decoder of the decoding apparatus of Figure 11 may perform S1000 to S1020 of Figure 10, the residual processor of the decoding apparatus of Figure 11 may perform S1030 of Figure 10, and the adder of the decoding apparatus of Figure 11 may perform S1040 of Figure 10. Further, although not illustrated, a process of receiving prediction information for the current block may be performed by the entropy decoder of the decoding apparatus of Figure 11, and a process of deriving a prediction sample of the current block may be performed by the predictor of the decoding apparatus of Figure 11.

[0335] According to the present disclosure, residual coding efficiency can be improved.

[0336] Further, according to the present disclosure, the TSRC-enabled flag may be signaled when signal data hiding is not enabled by adjusting the signaling relationship between the signal data hiding-enabled flag and the TSRC-enabled flag, whereby, when RRC syntax is coded for the transform omission block because TSRC is not enabled, signal data hiding is not used to improve coding efficiency, and the overall residual coding efficiency may be improved by reducing the amount of bits being coded.

[0337] Further, according to the present disclosure, the signaling relationship between the dependent quantization-enabled flag and the TSRC-enabled flag may be established, and if dependent quantization is not enabled, the TSRC-enabled flag may be signaled, and thereby, if TSRC is not enabled and then RRC syntax is coded for the transform omission block, dependent quantization should not be used, so that the coding efficiency may be improved, and the overall residual coding efficiency may be improved by reducing the amount of bits being coded.

[0338] Further, according to the present disclosure, the signaling relationship between the transform omission enabled flag and the TSRC enabled flag can be established, and if transform omission is enabled, the TSRC enabled flag can be signaled, and thereby, the overall residual coding efficiency can be improved by reducing the amount of bits being coded.

[0339] In the embodiment described above, the methods are described based on a flowchart having a series of steps or blocks. The present disclosure is not limited to the order of the above steps or blocks. Some steps or blocks may occur simultaneously or in a different order than other steps or blocks as described above. Furthermore, those skilled in the art will understand that the steps shown in the above flowchart are not exclusive, that additional steps may be included, or that one or more steps in the flowchart may be deleted without affecting the scope of the present disclosure.

[0340] The embodiments described in this specification may be realized by being implemented in a processor, a microprocessor, a controller or a chip. For example, the functional units shown in each drawing may be realized by being implemented in a computer, a processor, a microprocessor, a controller or a chip. In this case, the information for implementation (e.g., information or instructions) or algorithm may be stored in a digital storage medium.

[0341] Furthermore, the decoding apparatus and the encoding apparatus to which the present disclosure is applied can be included in a multimedia broadcast transmission/reception apparatus, a mobile communication terminal, a home cinema video apparatus, a digital cinema video apparatus, a surveillance camera, a video chat apparatus, a real-time communication apparatus such as video communication, a mobile streaming apparatus, a storage medium, a recorder, a VoD service provider apparatus, an Over-the-Top (OTT) video apparatus, an Internet streaming service provider apparatus, a three-dimensional (3D) video apparatus, a teleconferencing video apparatus, a transportation user equipment (e.g., in-vehicle user equipment, an aircraft user equipment, a ship user equipment, etc.), and a medical video apparatus, and can be used to process video signals and data signals. For example, the Over-the-Top (OTT) video device may include a game console, a Blu-ray player, an Internet-enabled TV, a home theater system, a smartphone, a tablet PC, a Digital Video Recorder (DVR), and the like.

[0342] Additionally, the processing method to which the present disclosure applies may be produced in the form of a program that must be executed by a computer and may be stored on a computer-readable recording medium. Multimedia data having a data structure according to the present disclosure may also be stored on a computer-readable recording medium. Computer-readable recording media include all types of storage devices where data readable by a computer system is stored. Computer-readable recording media may include a BD, a Universal Serial Bus (USB), ROM, PROM, EPROM, EEPROM, RAM, CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, for example. Additionally, computer-readable recording media include media implemented in the form of carrier waves (e.g., transmission over the Internet). Furthermore, a bit stream generated by the encoding method may be stored on a computer-readable recording medium or may be transmitted over wired/wireless communication networks.

[0343] Furthermore, embodiments of the present disclosure may be implemented with a computer program product according to the program codes, and the program codes may be realized in a computer by embodiments of the present disclosure. The program codes may be stored on a carrier that is readable by a computer.

[0344] Figure 12 illustrates a structural diagram of a content streaming system to which the present disclosure is applied.

[0345] The content streaming system to which embodiments of the present disclosure apply may largely include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device.

[0346] The encoding server compresses content input from multimedia input devices such as a smartphone, a camera, a recorder, etc. into digital data to generate a bitstream and transmit the bitstream to the streaming server. As another example, when multimedia input devices such as smartphones, cameras, recorders, etc. directly generate a bitstream, the encoding server may be omitted.

[0347] The bitstream may be generated by an encoding method or a bitstream generation method to which embodiments of the present disclosure apply, and the streaming server may temporarily store the bitstream in the process of transmitting or receiving the bitstream.

[0348] The streaming server transmits multimedia data to the user device based on a user request via the web server, and the web server serves as a means to inform the user of a service. When the user requests a desired service from the web server, the web server delivers it to a streaming server, and the streaming server transmits multimedia data to the user. In this case, the content streaming system includes a separate control server. In this case, the control server serves to control a command/response between devices in the content streaming system.

[0349] The streaming server may receive content from a media storage and/or an encoding server. For example, when content is received from the encoding server, the content may be received in real time. In this case, in order to provide a smooth streaming service, the streaming server may store the bitstream for a predetermined time.

[0350] Examples of the user device may include a mobile phone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), navigation, a slate PC, tablet PCs, ultrabooks, wearable devices (e.g., smart watches, smart glasses, head-mounted displays), digital TVs, desktop computers, digital signage, and the like. Each server in the content streaming system may be operated as a distributed server, in which case data received from each server may be distributed.

[0351] The claims described in the present disclosure may be combined in a variety of ways. For example, the technical features of the method claims of the present disclosure may be combined to be implemented as an apparatus, and the technical features of the apparatus claims of the present disclosure may be combined to be implemented as a method. Furthermore, the technical features of the method claim of the present disclosure and the technical features of the apparatus claim may be combined to be implemented as an apparatus, and the technical features of the method claim of the present disclosure and the technical features of the apparatus claim may be combined to be implemented as a method.

Claims (3)

1. Image decoding device, CHARACTERIZED by the fact that it comprises: a memory; and at least one processor connected to the memory, the at least one processor configured to: obtain a dependent quantization-enabled flag from a bit stream, wherein the dependent quantization-enabled flag equal to 1 represents that dependent quantization is enabled, and the dependent quantization-enabled flag equal to 0 represents that dependent quantization is disabled, obtain a Transform Omission Residual Coding (TSRC)-disabled flag based on the dependent quantization-enabled flag, wherein the TSRC-disabled flag equal to 1 represents that a residual coding syntax is used, and the TSRC-disabled flag equal to 0 represents that a TSRC syntax is used, obtain residual information for a current block based on the TSRC-disabled flag, derive residual samples of the current block based on the residual information, and generate a reconstructed figuration based on the residual samples, wherein the TSRC-disabled flag is obtained from the following: from the bitstream based on a value of the dependent quantization-enabled flag being equal to 0, and wherein the TSRC-disabled flag is obtained from a slice header of the bitstream. 2. Image encoding device, CHARACTERIZED by the fact that it comprises: a memory; and at least one processor connected to the memory, the at least one processor configured to: encode a dependent quantization-enabled flag, wherein the dependent quantization-enabled flag equal to 1 represents that dependent quantization is enabled, and the dependent quantization-enabled flag equal to 0 represents that dependent quantization is disabled, encode a Transform Omission Residual Coding (TSRC)-disabled flag based on the dependent quantization-enabled flag, wherein the TSRC-disabled flag equal to 1 represents that a residual coding syntax is used, and the TSRC-disabled flag equal to 0 represents that a TSRC syntax is used, encode residual information for a current block based on the TSRC-disabled flag, and generate a bitstream including the dependent quantization-enabled flag, the TSRC-disabled flag, and the residual information, wherein the TSRC-disabled flag is encoded in the bitstream based on a value of the dependent quantization-enabled flag being equal to 0, and wherein the TSRC-disabled flag is encoded in a slice header of the bitstream. 3. An apparatus for transmitting data for image information, comprising: at least one processor configured to: encode a dependent quantization-enabled flag, wherein the dependent quantization-enabled flag equal to 1 represents that dependent quantization is enabled, and the dependent quantization-enabled flag equal to 0 represents that dependent quantization is disabled, encode a Transform Omission Residual Coding (TSRC)-disabled flag based on the dependent quantization-enabled flag, wherein the TSRC-disabled flag equal to 1 represents that a residual coding syntax is used, and the TSRC-disabled flag equal to 0 represents that a TSRC syntax is used, encode residual information for a current block based on the TSRC-disabled flag, and generate a bit stream including the dependent quantization-enabled flag, the TSRC-disabled flag, and the information residuals; and a transmitter configured to transmit the data including the bit stream, wherein the TSRC-disabled flag is encoded in the bit stream based on a value of the dependent quantization-enabled flag being equal to 0, and wherein the TSRC-disabled flag is encoded in a slice header of the bit stream.