CN106373098B - Random impulse noise removal method based on dissimilar pixel statistics - Google Patents
Random impulse noise removal method based on dissimilar pixel statistics Download PDFInfo
- Publication number
- CN106373098B CN106373098B CN201610769889.9A CN201610769889A CN106373098B CN 106373098 B CN106373098 B CN 106373098B CN 201610769889 A CN201610769889 A CN 201610769889A CN 106373098 B CN106373098 B CN 106373098B
- Authority
- CN
- China
- Prior art keywords
- pixel
- noise
- image
- pixels
- window
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T5/00—Image enhancement or restoration
- G06T5/70—Denoising; Smoothing
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/20—Special algorithmic details
- G06T2207/20024—Filtering details
- G06T2207/20032—Median filtering
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Image Processing (AREA)
- Image Analysis (AREA)
Abstract
The present invention relates to image processing fields, to propose a kind of new random impulsive noise point detecting method, and there is preferable noise measuring ability, and the random impulsive noise that can be effectively removed in image to the median filtering of noise image application enhancements according to testing result.Thus, the technical solution adopted by the present invention is that, based on the method for suppressing random impulsive noise of non-similar pixel statistics, step is: determining the substantially distribution situation of image border first, and the difference according to edge degree of strength determines the threshold value T slightly determined for non-similar pixel;The pixel in image around each pixel is handled simultaneously, determine whether child window center pixel is the non-similar pixel for being detected pixel, the non-similar pixel number NDP on last statistic mixed-state point periphery determines whether the test point is noise by being compared with non-similar pixel number threshold value NDPCT;Median filter process is used to noise spot.Present invention is mainly applied to image processings.
Description
Technical field
The present invention relates to image processing fields, more particularly to when carrying out random impulsive noise removal processing to image, right
Problem is determined and filtered out in the differentiation of noise spot.Concretely relate to the image denoising method using block sorting detection noise.
Background technique
The random impulsive noise of image is mainly derived from the processes such as image acquisition, transmission and analog-to-digital conversion, its main feature is that making an uproar
Sound position and gray value are that random and with surrounding point is discontinuous, it appears that seem random scatter on the image bright or dark
Spot.Noise in image has seriously affected the quality of image, is effectively removed random impulsive noise present in image and makes an uproar
Sound, while the detailed structure of image can be retained again, for example edge and texture are a major issues of image procossing research.Linearly
Filtering tends not to random impulse noise mitigation, it is therefore desirable to use nonlinear filtering.Median filtering is a kind of most common non-
Linear filter method, can preferably inhibit the random impulsive noise in image, but due to its there is no distinguish image pixel and
Noise pixel handles all pixels point in image, filtered image image border more easy to be lost and detailed information.Such as
What accurately determines the position of random impulsive noise, i.e. noise measuring is the committed step that random impulsive noise removes.
Summary of the invention
In order to overcome the deficiencies of the prior art, the present invention is directed to propose a kind of new random impulsive noise point detecting method, and
According to testing result to the median filtering of noise image application enhancements, there is preferable noise measuring ability, and can be effective
Ground removes the random impulsive noise in image.For this purpose, the technical solution adopted by the present invention is that, based on non-similar pixel statistics with
Machine impulsive noise minimizing technology, step is: determining the substantially distribution situation of image border first, and according to edge degree of strength
Difference determines the threshold value T slightly determined for non-similar pixel;Simultaneously to the pixel in image around each pixel at
Reason, to be detected pixel xi,jCentered on establish the exposure mask of one (2N+1) × (2N+1), extract 8 from this big window
A child window, the division mode that child window divides is arranged counterclockwise, these child windows include detected pixel;It counts respectively
Calculate each child window central pixel point and tested measuring point xi,jAbsolute pixel gray scale difference value dk, subscript k represents k-th of window, right
In child window Ω1, central pixel point xi-1.j-1, dkIs defined as:
dk=| xi,j-xi-1.j-1|
If meeting dk>=T continues to determine, pixel mean differential index AD is calculated in the child window, if
Meet dk≥ADkDetermine that the child window center pixel is the non-similar pixel for being detected pixel, last statistic mixed-state point periphery
Non- similar pixel number NDP, by be compared with non-similar pixel number threshold value NDPCT determine the test point whether be to make an uproar
Sound;Remaining child window and so on;Median filter process is used to noise spot.
Difference according to edge degree of strength determines that the threshold value T slightly determined for non-similar pixel is comprised the concrete steps that, respectively
Calculate the Ω of arranged counterclockwise1, Ω2, Ω3, Ω4The intermediate value of four child window all pixels point gray values is simultaneously ranked up, sequence
Result afterwards is denoted as m1≤m2≤m3≤m4, roughly determined in this exposure mask according to the numerical value of this four gray values and sequence
Edge distribution;Enable Δ ME=m4-m1,ΔMI=m3-m2, Δ MEWith Δ MIThis four sub- window pixel gray scale entirety differences are provided
Measurement, Δ MEWith Δ MIValue be divided into three kinds of situations, and accordingly three kinds of situations judge this center pixel surrounding edge point
Cloth situation, wherein carrying out Δ MEWith Δ MIThreshold value T is taken when comparing to determiner;The first situation indicates to work as Δ MI≥TrWhen, judgement
There are stronger details or grain distribution in this window;Second situation indicates Δ MI≤TrAnd Δ ME≥TrWhen, that is, judge this
There are part edge distribution, i.e., weak edge in window;The third situation indicates to work as Δ ME≤TrWhen, judge this window be it is smooth,
There is no image border;Different threshold value T is respectively adopted to determine non-similar pixel in the different edge of degree of strength.
Pixel mean differential index AD is the index for measuring peripheral image vegetarian refreshments and central point mean differential, each sub- window
Mouth central point pixel x0Surrounding has m neighborhood territory pixel, and neighborhood territory pixel value is xiThen AD is defined as
The result of noise measuring is charged to and is instructed in matrix, it is identical as image size to instruct matrix, and only there are two value,
" 1 " representative image corresponding position is noise pixel point, and " 0 " representative image corresponding position is normal pixel, is adopted to noise image
Image can be denoised with median filtering, due to having indicated the position of normal pixel in instructing matrix, when filtering is selected
It takes the normal pixel point on noise pixel periphery and acquires intermediate value substitution current noise pixel.
When using median filter process to noise image, according to the noise measuring instructed in matrix as a result, by noise picture
The gray value of element is set as the intermediate value of all normal pixel point gray values in 3 × 3 neighborhood window of noise spot.
Carry out repeated detection using the method for iteration and restore image to obtain preferable noise filtering effect, and into
When the multiple noise filtering of row, neighbour of the noise pixel of last missing inspection comprising more approximate normal gray values in restoring image
The number of domain pixel, the non-similar pixel in neighborhood increases therewith, and non-similar pixel number compares threshold value NDPCT also will be with
The number of iterations increases and increases.
The features of the present invention and beneficial effect are:
1. the invention proposes a kind of improvement median filtering calculations for being detected and being removed for common random impulsive noise
Method determines rough comparison threshold value, this both reduced when carrying out noise measuring according to the edge of varying strength or details first
The child window number that pixel mean differential index calculates, and improve the verification and measurement ratio of impulsive noise.
2. improved median filter method is combined closely with testing result, when filtering, which weeds out, has been detected as noise
Pixel improves the denoising effect at median filtering blurred picture edge, protects the details of image.
Detailed description of the invention:
Fig. 1 noise measuring flow chart.
Child window divides schematic diagram when Fig. 2 noise measuring.
Fig. 3 edge detection texture estimation schematic diagram.
(a) weak edge (c) smooth region of strong edge (b).
Specific embodiment
The invention proposes a kind of new random impulsive noise point detecting methods, and answer according to testing result noise image
With improved median filtering, this method has preferable noise measuring ability, and can be effectively removed random in image
Impulsive noise.
Fig. 1 is noise measuring flow chart, and the present invention determines the substantially distribution situation of image border first, and strong according to edge
The difference of weak degree determines the threshold value T slightly determined for non-similar pixel;Simultaneously to the picture in image around each pixel
Element is handled, to be detected pixel xi,jCentered on establish the exposure mask of one (2N+1) × (2N+1), 5 × 5 exposure mask is preferred
But be not limited to the size of exposure mask, 8 child windows extracted from this big window, child window division methods as shown in Fig. 2, this
A little window includes detected pixel.Calculate separately each child window central pixel point and tested measuring point xi,jAbsolute picture
Plain gray scale difference value dk, with child window Ω1(central pixel point xi-1.j-1) for, d1Is defined as:
d1=| xi,j-xi-1.j-1|,
If meeting dk>=T continues to determine, pixel mean differential index AD is calculated in the child window, if
Meet dk≥ADk, that is, can determine that the child window center pixel is the non-similar pixel for being detected pixel, subscript k is represented k-th
Window, the non-similar pixel number NDP on last statistic mixed-state point periphery, by being carried out with non-similar pixel number threshold value NDPCT
Compare and determines whether the test point is noise.
When edge detection, Ω in Fig. 2 is calculated separately1, Ω2, Ω3, Ω4In four child window all pixels point gray values
It is worth and is ranked up, the result after sequence is denoted as m1≤m2≤m3≤m4, can be thick according to the numerical value of this four gray values and sequence
Slightly determine the edge distribution in this exposure mask.Enable Δ ME=m4-m1,ΔMI=m3-m2, Δ MEWith Δ MIThis four can be provided
The measurement of child window pixel grey scale entirety difference, Δ MEWith Δ MIValue be roughly divided into such as three kinds of situations of figure, and judge accordingly
The distribution situation of this center pixel surrounding edge, wherein carrying out Δ MEWith Δ MIThreshold value T is taken when comparing to determiner.In figure
(a) situation indicates to work as Δ MI≥TrWhen, it can determine whether there is stronger details or grain distribution in this window.(b) situation indicates in figure
ΔMI≤TrAnd Δ ME≥TrWhen, that is, it can determine whether there is part edge distribution in this window, i.e., weak edge;(c) situation indicates in figure
As Δ ME≤TrWhen, can determine whether this window be it is smooth, almost without image border;It adopts respectively at the different edge of degree of strength
Non- similar pixel is determined with different threshold value T.
Pixel mean differential index AD is the index for measuring peripheral image vegetarian refreshments and central point mean differential.Each sub- window
Mouth central point pixel x0Surrounding has m neighborhood territory pixel (m=8 here), and neighborhood territory pixel value is xi(1≤i≤8) then AD is defined as
The result of noise measuring is charged to and is instructed in matrix, it is identical as image size to instruct matrix, and only there are two value,
" 1 " representative image corresponding position is noise pixel point, and " 0 " representative image corresponding position is normal pixel, is adopted to noise image
Image can be denoised with improved median filtering, due to having indicated the position of normal pixel in instructing matrix, be filtered
The normal pixel point on noise pixel periphery is chosen when wave and acquires intermediate value substitution current noise pixel.
During removing random impulsive noise, since noise position and gray value have randomness, one-time detection is past
It is past to obtain accurate testing result, the noise pixel comprising many missing inspections, so the method using iteration is repeatedly examined
Preferable noise filtering effect can be obtained by surveying and restoring image.And when carrying out multiple noise filtering, last missing inspection is made an uproar
Acoustic image element includes the neighborhood territory pixel of more approximate normal gray values, of the non-similar pixel in neighborhood in restoring image
Number increases therewith, causes normal pixel point by the generation of erroneous detection such case, non-similar pixel number to reduce successive ignition
Comparing threshold value NDPCT will also increase as the number of iterations increases.
The implementation steps of the invention is divided to detection noise and removal two step of noise to carry out.It is random to being added when to noise measuring
The image of impulsive noise is detected, and pixel is used by edge and noise measuring centered on each of image pixel
Be grayscale image that contrast is 255, picture size is 512 × 512, and Size of Neighborhood is chosen for 5 × 5, threshold when edge detection
Value Tr40 are set as, and uses different comparison threshold value T, i.e. smooth region, weak edge, strong edge ratio for the edge of varying strength
It is respectively T1, T2, T3 compared with threshold value, meeting the following conditions T1≤T2≤T3., selection [10,25,40] is used as different sides respectively here
The comparison threshold value of edge.Non- similar pixel number compares threshold value NDPCT and increases as the number of iterations n increases, and the number of iterations is more,
It has more normal pixels and is erroneously detected as noise pixel, the edge of blurred picture, the present invention is used uniformly iteration time twice
Number, in noise detecting process twice, non-similar pixel number compares threshold value NDPCT and is set to 5,6 to improve impulsive noise
Verification and measurement ratio.
It, as a result, will according to the noise measuring instructed in matrix when using improved median filter process to noise image
The gray value of noise pixel is set as the intermediate value of all normal pixel point gray values in 3 × 3 neighborhood window of noise spot.
The implementation steps of the invention is divided to detection noise and removal two step of noise to carry out.It is random to being added when to noise measuring
The image of impulsive noise is detected, and pixel is used by edge and noise measuring centered on each of image pixel
Be grayscale image that contrast is 255, picture size is 512 × 512, and Size of Neighborhood is chosen for 5 × 5, threshold when edge detection
Value Tr40 are set as, and uses different comparison threshold value T, i.e. smooth region, weak edge, strong edge ratio for the edge of varying strength
It is respectively T1, T2, T3 compared with threshold value, meeting the following conditions T1≤T2≤T3., selection [10,25,40] is used as different sides respectively here
The comparison threshold value of edge.Non- similar pixel number compares threshold value NDPCT and increases as the number of iterations n increases, and the number of iterations is more,
It has more normal pixels and is erroneously detected as noise pixel, the edge of blurred picture, the present invention is used uniformly iteration time twice
Number, in noise detecting process twice, non-similar pixel number compares threshold value NDPCT and is set to 5,6 to improve impulsive noise
Verification and measurement ratio.
It, as a result, will according to the noise measuring instructed in matrix when using improved median filter process to noise image
The gray value of noise pixel is set as the intermediate value of all normal pixel point gray values in 3 × 3 neighborhood window of noise spot.
Claims (4)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610769889.9A CN106373098B (en) | 2016-08-30 | 2016-08-30 | Random impulse noise removal method based on dissimilar pixel statistics |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610769889.9A CN106373098B (en) | 2016-08-30 | 2016-08-30 | Random impulse noise removal method based on dissimilar pixel statistics |
Publications (2)
Publication Number | Publication Date |
---|---|
CN106373098A CN106373098A (en) | 2017-02-01 |
CN106373098B true CN106373098B (en) | 2019-04-23 |
Family
ID=57901918
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201610769889.9A Expired - Fee Related CN106373098B (en) | 2016-08-30 | 2016-08-30 | Random impulse noise removal method based on dissimilar pixel statistics |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN106373098B (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109035173B (en) * | 2018-08-15 | 2022-05-17 | 深圳大学 | Image filtering method, storage medium and terminal device |
CN109598723B (en) * | 2018-12-11 | 2021-09-07 | 讯飞智元信息科技有限公司 | Image noise detection method and device |
CN109920113B (en) * | 2019-03-13 | 2020-08-18 | 安徽龙运智能科技有限公司 | Control method of intelligent lock system and intelligent lock system |
CN110706171B (en) * | 2019-09-26 | 2024-04-26 | 中国电子科技集团公司第十一研究所 | Image noise reduction method and device |
CN113628118B (en) * | 2020-05-06 | 2023-12-08 | 北京君正集成电路股份有限公司 | Method for denoising and filtering in flat area |
CN112446838B (en) * | 2020-11-24 | 2024-07-12 | 海南大学 | Image noise detection method and device based on local statistical information |
CN113920068B (en) * | 2021-09-23 | 2022-12-30 | 北京医准智能科技有限公司 | Body part detection method and device based on artificial intelligence and electronic equipment |
CN116071220B (en) * | 2023-03-06 | 2023-06-20 | 浙江华感科技有限公司 | Image window data processing method, device, equipment and medium |
CN116681703B (en) * | 2023-08-03 | 2023-10-10 | 杭州鸿世电器股份有限公司 | Intelligent switch quality rapid detection method |
CN117676038B (en) * | 2024-01-30 | 2024-04-05 | 北京点聚信息技术有限公司 | Electronic license data secure sharing method and system |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101087365A (en) * | 2006-06-10 | 2007-12-12 | 中兴通讯股份有限公司 | A method for filtering image mixed noise |
CN105243649A (en) * | 2015-11-09 | 2016-01-13 | 天津大学 | Image denoising method based on secondary noise point detection |
CN105787902A (en) * | 2016-03-22 | 2016-07-20 | 天津大学 | Image noise reduction method which utilizes partitioning ordering to detect noise |
-
2016
- 2016-08-30 CN CN201610769889.9A patent/CN106373098B/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101087365A (en) * | 2006-06-10 | 2007-12-12 | 中兴通讯股份有限公司 | A method for filtering image mixed noise |
CN105243649A (en) * | 2015-11-09 | 2016-01-13 | 天津大学 | Image denoising method based on secondary noise point detection |
CN105787902A (en) * | 2016-03-22 | 2016-07-20 | 天津大学 | Image noise reduction method which utilizes partitioning ordering to detect noise |
Non-Patent Citations (4)
Title |
---|
A Universal Noise Removal Algorithm with an Impulse Detector;Roman Garnett 等;《IEEE Transactions on Image Processing》;20051231;第1-7页 |
一种去除图像混合噪声的新方法;杨辉 等;《衡阳师范学院学报》;20101231;第31卷(第6期);第36-39页 |
一种有效的混合噪声滤波算法;王建勇 等;《信息技术》;20051231;第48-50页 |
数字图像混合噪声滤除算法研究;陈秉涛;《中国优秀硕士学位论文全文数据库 信息科技辑》;20121015;正文第5章 |
Also Published As
Publication number | Publication date |
---|---|
CN106373098A (en) | 2017-02-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN106373098B (en) | Random impulse noise removal method based on dissimilar pixel statistics | |
CN109870461B (en) | Electronic components quality detection system | |
CN105787902B (en) | Utilize the image denoising method of block sorting detection noise | |
Jafar et al. | Efficient improvements on the BDND filtering algorithm for the removal of high-density impulse noise | |
CN102156996B (en) | Image edge detection method | |
CN103778611B (en) | Utilize the switch weight vectors median filter method of rim detection | |
CN114549441B (en) | Straw defect detection method based on image processing | |
CN109472788B (en) | A method for detecting flaws on the surface of aircraft rivets | |
CN103400357B (en) | A kind of method removing image salt-pepper noise | |
CN113436216B (en) | Electrical equipment infrared image edge detection method based on Canny operator | |
CN104899842B (en) | The adaptive extreme value median filter method of sequence for remote line-structured light image | |
CN105225244A (en) | Based on the noise detection method that minimum local mean square deviation calculates | |
CN106918602A (en) | A kind of detection method of surface flaw based on machine vision of robust | |
CN117522778A (en) | Hollow brick flaw detection system | |
CN102118547A (en) | Image weighted filtering method | |
CN112330633A (en) | A fault image segmentation method based on self-adaptive band-pass filtering for damaged jumper tape | |
CN102830045A (en) | Fabric spray rating objective evaluating method based on image processing | |
CN105469413B (en) | It is a kind of based on normalization ring weighting without refer to smear restoration image synthesis method for evaluating quality | |
JP2014238789A (en) | Image processing program, image processing method and image processor | |
Kumar et al. | Adaptive edge discriminated median filter to remove impulse noise | |
Karthikeyan et al. | Hybrid approach of efficient decision-based algorithm and fuzzy logic for the removal of high density salt and pepper noise in images | |
Guo et al. | An adaptive soft-morphological-gradient-filter-for-edge-detection | |
Russo | New method for measuring the detail preservation of noise removal techniques in digital images | |
Chudasama et al. | Survey on Various Edge Detection Techniques on Noisy Images | |
Ahmed | Image enhancement and noise removal by using new spatial filters |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190423 Termination date: 20190830 |
|
CF01 | Termination of patent right due to non-payment of annual fee |