WO2018120011A1 - Projected image correction method and device, and robot - Google Patents

Abstract

Provided are a projected image correction method and device, and a robot. The correction method comprises: acquiring a length of a projection optical axis (AD) and a distance between a projection point (A) and an edge point of a projected image, the edge point of the projected image being an intersection point of a vertical line passing through an optical axis point (D) of the projection optical axis and an edge of the projected image (100); and calculating, according to a field of view, the length of the projection optical axis and the projection point (A), a deformation ratio of a pixel of the projected image on a projection plane (30) (200); and adjusting the projected image according to the deformation ratio (300). By performing correction, even if states of the projection optical axis (AD) and the projection plane (30) are not ideal, the projected image can be displayed normally, thereby lowering a requirement on an environment in a projection process, and expanding scenarios in which a projection device (20) can be normally used.

Description

Projection image correction method, correction device, and robot Technical field

The present invention relates to the field of projection technology, and in particular, to a projection image correction method, a calibration device, and a robot.

Background technique

In the currently used optical projection technology, in order to obtain a clear and accurately focused projection image, a flat wall or curtain is required as a projection surface. Moreover, according to the optical principle of the projection, as shown in FIG. 1, the projection optical axis A should maintain a positional relationship with the projection surface (wall or curtain), otherwise the projection image may be distorted on the projection surface.

With the continuous development of robotics, miniaturization and intelligence, robots (or other similar smart devices) are increasingly choosing to use projection devices as a way to present images or content to users, the application of optical projection devices. The scope is also more and more extensive.

In the process of implementing the present invention, the inventors have found that the related art has the following problem: during the use of the projection device, due to the limitation of different scenes, the ideal state in which the projection optical axis A and the projection surface are kept perpendicular to each other cannot be maintained, for example, projection. When the device is applied to the robot, since the user's optimal viewing angle is the central area of the image, if the robot also projects the optical axis perpendicular to the wall or the projection screen, it is likely to keep the user behind.

In the projection process, if the tilt angle between the projection optical axis and the projection surface is large, the projected image will exhibit a very significant non-proportional stretching distortion, and the user experience is extremely poor.

Summary of the invention

The main purpose of the embodiment of the present invention is to reduce the stretching and distortion of the projected image when the projection optical axis and the projection surface have an oblique angle, and improve the stability of the projected image.

In order to solve the above technical problem, one technical solution adopted by the embodiment of the present invention is to provide a projection image correction method. The method includes:

Obtaining a length of the projection optical axis and a distance between the projection point and the edge point of the projection image; the edge point of the projection image is: an intersection of a perpendicular line passing through the optical axis point of the projection optical axis and an edge of the projected image; according to the angle of view, A projection optical axis length and a distance between the projection point and the edge point of the projection image, calculating a deformation ratio of the pixel of the projection image on the projection surface; and adjusting the projection image according to the deformation ratio.

Optionally, the distance between the projection point and the edge point of the projected image includes: a projection point and a horizontal a first lateral distance and a second lateral distance between edge points of the projected image formed by the straight line passing through the optical axis point, and a first longitudinal distance between the projected point and the edge point of the projected image formed by the straight line passing through the optical axis point vertically And the second longitudinal distance.

Optionally, the angle of view includes: a width angle in a horizontal direction and an elevation angle in a vertical direction; the projection surface is perpendicular to a horizontal plane, and the projection optical axis is parallel to a horizontal plane.

The calculating the deformation ratio of the pixel points on the projection surface of the projection image specifically includes: calculating a lateral deformation of the pixel of the projection image on the projection surface according to the width angle, the length of the projection optical axis, the first lateral distance, and the second lateral distance The ratio is calculated according to the height angle and the lateral deformation ratio, and the longitudinal deformation ratio of the pixel on the projection surface of the projected image is calculated.

Optionally, the projected image has m pixels in the lateral direction and n pixels in the longitudinal direction, and the longitudinal deformation ratio corresponding to the m pixels in the lateral direction is calculated by the following formula:

b ₁ =n×a ₁

b ₂ =n×a ₁ +a ₁ ×tanγ

b ₃ =n×a ₁ +(a ₁ +a ₂ )×tanγ

......

b _m =n×a ₁ +(a ₁ +a ₂ +...+a _m-1 )×tanγ

Wherein a ₁ , a ₂ , . . . , a _m is a lateral deformation ratio corresponding to m pixel points in the lateral direction, and γ is the elevation angle, and b ₁ , b ₂ , b ₃ , . . . , b _m are The longitudinal deformation ratio of the m pixel points in the lateral direction.

Optionally, the angle of view includes: a width angle in a horizontal direction and a height angle in a vertical direction; and calculating a deformation ratio of the pixel points on the projection surface of the projection image specifically includes: according to the height angle, the length of the projection optical axis a first longitudinal distance and a second longitudinal distance, and calculating a longitudinal deformation ratio of the pixel points of the projected image on the projection surface;

Calculating a lateral deformation ratio of the pixel points of the projected image on the projection surface according to the width angle and the longitudinal deformation ratio. Optionally, the adjusting the projection image according to the deformation ratio comprises:

Compressing or stretching each line of the projected image to a normal display width according to the lateral deformation ratio;

Each column of the projected image is compressed or stretched to a normal display height according to the longitudinal deformation ratio.

Optionally, the calculating a ratio of the lateral deformation of the pixel on the projection surface of the projection image includes:

Calculating the optical path angle of the pixel according to the width angle;

Calculating a first angle between the projection optical axis and the projection surface according to the width angle, the length of the projection optical axis, and the distance between the edge of the projected image and the projection point;

According to the optical path angle and the first angle, the lateral deformation ratio of the pixel points is calculated. Optionally, the optical path angle of the lateral deformation ratio is specifically calculated by the following method:

Calculate the standard width of the pixel by the following formula:

among them,

Is half of the width angle; a is the standard width of the pixel, n is the number of pixels included in each line in the projected image, and L is the length of the projected optical axis

The optical path angle corresponding to each pixel point is sequentially calculated by the following formula:

α _n is the optical path angle corresponding to the nth pixel point.

Optionally, the first angle of the lateral deformation ratio is specifically calculated by the following method:

Calculate the distance between the optical axis point of the projected optical axis and the edge point of the projected image by the following formula:

Where DC is the distance between the optical axis point of the projection optical axis on the projection surface and the edge point of the projected image, L is the length of the projection optical axis, and L ₁ is the distance between the projection point and the edge point of the projected image.

Half of the width angle;

According to the distance between the optical axis point and the edge point of the projected image, the first angle is calculated by the following formula:

Where β is the first angle.

.

Optionally, the lateral deformation ratio is calculated by the following formula:

Where y is the width of the n-1th pixel point; z is the width of the nth pixel point;

For the lateral deformation ratio, α _n is the optical path angle of the nth pixel.

Optionally, the adjusting the projection image according to the deformation ratio comprises:

Generating a corresponding calibration curve according to the deformation ratio;

Using the calibration curve, correspondingly adjusting a shape size of the projected image;

Projecting the adjusted projected image onto the projection surface.

In order to solve the above technical problem, still another technical solution adopted by the embodiment of the present invention is to provide a projection image correcting device. The device comprises: a ranging module, configured to acquire a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: a perpendicular line of the optical axis point passing through the projection optical axis and an edge of the projected image Intersection point;

a calculation module, configured to calculate a deformation ratio of the pixel of the projection image on the projection surface according to the angle of view, the length of the projection optical axis, and the distance between the projection point and the edge point of the projection image;

And an adjustment module, configured to adjust the projected image according to the deformation ratio.

Optionally, the distance between the projection point and the edge point of the projected image comprises: a first lateral distance and a second lateral distance between the projection point and a projection image edge point formed by a straight line passing through the optical axis point, and the projection point and A first longitudinal distance and a second longitudinal distance between edge points of the projected image formed by the straight line passing perpendicular to the optical axis point.

Optionally, the angle of view includes: a width angle in a horizontal direction and an elevation angle in a vertical direction; the projection surface is perpendicular to a horizontal plane, and the projection optical axis is parallel to a horizontal plane.

The calculation module is specifically configured to: calculate a lateral deformation ratio of the pixel of the projection image on the projection surface according to the width angle, the projection optical axis length, the first lateral distance, and the second lateral distance. Optionally, the projected image has m pixels in the lateral direction and n pixels in the longitudinal direction, and the longitudinal deformation ratio corresponding to the m pixels in the lateral direction is calculated by the following formula;

The calculation module is specifically configured to calculate a longitudinal deformation ratio corresponding to m pixel points in the lateral direction by using an algorithm:

b ₁ =n×a ₁

b ₂ =n×a ₁ +a ₁ ×tanγ

b ₃ =n×a ₁ +(a ₁ +a ₂ )×tanγ

......

b _m =n×a ₁ +(a ₁ +a ₂ +...+a _m-1 )×tanγ

Wherein a ₁ , a ₂ , . . . , a _m is a lateral deformation ratio corresponding to m pixel points in the lateral direction, and γ is the elevation angle, and b ₁ , b ₂ , b ₃ , . . . , b _m are The longitudinal deformation ratio of the m pixel points in the lateral direction.

Optionally, the angle of view includes: a width angle in a horizontal direction and an elevation angle in a vertical direction;

The calculating module is specifically configured to: calculate a longitudinal deformation ratio of a pixel of the projection image on the projection surface according to the height angle, the length of the projection optical axis, the first longitudinal distance, and the second longitudinal distance;

Calculating a lateral deformation ratio of the pixel points of the projected image on the projection surface according to the width angle and the longitudinal deformation ratio.

Optionally, the adjusting module is specifically configured to:

Compressing or stretching each line of the projected image to a normal display width according to the lateral deformation ratio;

Each column of the projected image is compressed or stretched to a normal display height according to the longitudinal deformation ratio.

Optionally, the calculating module is specifically configured to: calculate an optical path angle of the pixel according to the width angle; calculate a projection optical axis and a projection surface according to the width angle, the length of the projection optical axis, and the distance between the edge of the projected image and the projection point. The first angle between the two; according to the optical path angle and the first angle, the lateral deformation ratio of the pixel point is calculated.

Optionally, the computing module is specifically configured to:

Calculate the standard width of the pixel by the following formula:

among them,

Is half of the width angle; a is the standard width of the pixel, n is the number of pixels included in each row in the projected image, and L is the length of the projection optical axis;

The optical path angle corresponding to each pixel point is sequentially calculated by the following formula:

α _n is the optical path angle corresponding to the nth pixel point.

Optionally, the computing module is specifically configured to:

The first angle of the lateral deformation ratio is specifically calculated by the following method:

Calculate the distance between the optical axis point of the projected optical axis and the edge point of the projected image by the following formula:

Where DC is the distance between the optical axis point of the projection optical axis on the projection surface and the edge point of the projected image, L is the length of the projection optical axis, and L ₁ is the distance between the projection point and the edge point of the projected image.

Half of the width angle;

According to the distance between the optical axis point and the edge point of the projected image, the first angle is calculated by the following formula:

Where β is the first angle.

Optionally, the calculating module is specifically configured to: calculate the deformation ratio by using the following formula:

Where y is the width of the n-1th pixel point; z is the width of the nth pixel point;

For the lateral deformation ratio, α _n is the optical path angle of the nth pixel.

Optionally, the adjusting module is further configured to: generate a corresponding calibration curve according to the deformation ratio; use the calibration curve to adjust a shape size of the projected image; and project the adjusted projection image to the On the projection surface.

In order to solve the above technical problem, another technical solution adopted by the embodiment of the present invention is to provide at least one projection device, a processor, and a ranging unit;

The ranging unit is configured to acquire a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: an intersection of a perpendicular line passing through the optical axis point of the projection optical axis and an edge of the projection image; The processor is configured to calculate a deformation ratio of a pixel of the projection image on the projection surface according to the length of the projection optical axis acquired by the ranging unit, the distance between the projection point and the edge point of the projection image, and the angle of view of the projection device, and according to The deformation ratio adjusts a projection image; the projection device is configured to project the adjusted projection image onto the projection surface.

Optionally, the robot further includes a power device that drives the robot to move during projection of the projection device; the ranging module acquires a length of the projection optical axis and a distance between the projection point and the edge point of the projected image in real time; The processor is further configured to adjust a projection image according to the length of the projection optical axis and the distance between the projection point and the edge point of the projection image; the projection device is configured to project the adjusted projection image onto the projection surface .

In order to solve the above technical problem, still another technical solution adopted by the embodiment of the present invention is to provide a computer program product including a software code portion. The software code portion is configured to perform the method steps as described above when run in a memory of the computer.

The projection image correction method provided by the embodiment of the present invention calculates the deformation ratio of the projection image by the distance parameter and the angle of view of the projection device itself in a geometrical mathematical manner, and performs automatic correction accordingly. Through the correction process, the normal display of the projected image can still be maintained between the projection optical axis and the projection surface in a non-ideal state, thereby reducing the environmental requirements during the projection process, and expanding the scene in which the projection device can be normally used.

DRAWINGS

Figure 1 is a schematic view of a typical optical projection device on a projection surface;

2 is an application environment of a method for performing a projection image correction according to an embodiment of the present invention;

3 is a schematic diagram showing a pixel point distribution of a typical projected image;

4 is a flowchart of a method for correcting a projected image according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a method for calculating a lateral deformation ratio according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic diagram of a usage scenario of a projection apparatus according to an embodiment of the present disclosure;

FIG. 7 is a functional block diagram of a projection image correction apparatus according to an embodiment of the present invention;

FIG. 8 is a structural block diagram of an electronic device according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of projections according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

An optical projection device is a commonly used device that can provide a larger display pattern with a smaller device volume. As shown in Fig. 1, in an optical projection device, it has a fixed projection optical axis AD and a projection surface for projection image display. The focus D of the projection optical axis AD on the projection surface is used to determine the position of the projected image on the projection surface, and the focus D is located at the center of the projected image. The optical projection device outputs a projection image to the projection surface at the projection point A according to the input image or other type of data signal, and presents it to the user.

FIG. 2 is an application environment of a method for performing a projection image correction according to an embodiment of the present invention. As shown in FIG. 2, the application environment includes a user 10, a projection device 20, a projection surface 30, a server 40, and a network 50.

User 10 can be any group of people having the same or similar operational behavior, such as a family, work group, or individual. The user 10 can interact with the projection device 20 by any suitable type, one or more user interaction devices, such as a mouse, keyboard, remote control, touch screen, somatosensory camera or smart wearable device, inputting instructions or controlling the projection device 20 to perform One or more operations that display a projected image on projection surface 30 for presentation to one or more users.

Projection device 20 can be any suitable type of optical projection device. In some embodiments, the projection device 20 can also be used as one of the functional modules integrated in a device having certain logic computing capabilities to provide one or more functions capable of meeting user requirements. For example, intelligent robots, laptops, sweeping robots, robot assistants, etc.

In some embodiments, the projection device 20 can also be disposed on a device having mobility capabilities, such as a robot with a power device or a sweeping robot. The device can move the projection device 20 according to a user's instructions or to meet a particular function, in accordance with a certain route or speed. In other embodiments, the projection device can also be disposed on a device having a distance measuring device. The ranging device may specifically be any suitable ranging device for obtaining a distance from the target, such as an infrared ranging, a laser ranging device, and the like.

The projection device 20 may also include one or more logical operation modules that perform any suitable type of function or operation in parallel, such as performing a particular function operation, in a single thread or multiple threads. The logic operation module can be any suitable type of electronic circuit or chip-type electronic device capable of performing logical operation operations, such as a single core processor, a multi-core processor, a graphics processing unit (GPU).

The device may further be provided with a meter stored and called for execution by the logic operation module. A storage medium of a computer executable program that is executed by the logic computing module to perform one or more steps of a corresponding function.

Server 30 can be any suitable electronic computing platform for performing account management. The user 10 can also interact with the server 40 by any suitable type, one or more user interaction devices, such as a mouse, keyboard, remote control, touch screen, somatosensory camera or smart wearable device, with input commands or control server 40 executing one One or more operations, such as outputting projected image data into the projection device 20.

Network 50 may be any suitable wired or wireless network to enable a communication connection between two devices, such as the Internet, a local area network, or a wired cable. Server 40 may establish a communication connection with one or more different projection devices 20 over network 50 to upload or dispatch data/instructions.

In this application environment, the calculation step of the projection image correction method provided by the embodiment of the present invention may be performed in any suitable device having logical operation capability, such as a server, a projection device, or a robot integrated with a projection device.

It should be noted that the projection image correction method provided by the embodiment of the present invention can be further extended to other suitable application environments with multiple account management requirements, and is not limited to the application environment shown in FIG. 2. Although only one user 10, one projection device 20, and one server 40 are shown in FIG. However, those skilled in the art can understand that the application environment may also include more or fewer users, projection devices, and servers in actual application processes.

Conventionally, as shown in FIG. 3, the projected image can be represented by an array of m columns and n rows of pixels. In the case where the projection device is not facing the projection surface, the projection image may have a deformation in the lateral direction x and the longitudinal direction y. The projection device can separately calculate the deformation ratio in the lateral direction x or the longitudinal direction y in the projected image, and adjust the projected image according to the deformation ratio.

FIG. 4 is a schematic diagram of a method for correcting a projected image according to an embodiment of the present invention. The projection image correction method can be performed in the application environment shown in FIG. 2 to ensure normal display of the projected image in the case where the projection device is not facing the projection surface.

As shown in FIG. 4, the method includes the following steps:

100: Acquire the length of the projection optical axis and the distance between the projection point and the edge point of the projected image. Wherein, the edge point of the projected image is an intersection of a perpendicular line passing through the optical axis point of the projection optical axis and an edge of the projected image.

As shown in FIG. 9, the projection optical axis corresponds to the optical axis point D on the projection surface. The distance between the projected optical axis length and the projected image edge points (such as point B and point C) can be obtained by the corresponding distance measuring device. Any suitable type of sensor or electronic device for calculating the distance, such as an infrared distance measuring device, can be used.

200: Calculate a deformation ratio of a pixel of the projection image on the projection surface according to the angle of view, the length of the projection optical axis, and the distance between the projection point and the edge point of the projection image.

In a normal projected image, the size between two adjacent pixels should remain equal, for example, x1 and x2 shown in Figure 3 should be equal. In the non-ideal case, due to the tilt of the projection optical axis, the pixel point size ratio changes, and the adjacent pixel points are not equal in size. Here, the term "deformation ratio" is used to describe the proportional change in the size of the above pixel.

The field of view is a parameter value determined by the hardware device of the projection device, which is related to the focal length and the like, and can be obtained by finding data inside the projection device, which can represent the field of view of the projected image. As shown in FIG. 9, the angle of view can be divided into two parameters: a width angle (angle BAC) and a height angle (angle B1AC1) in the horizontal direction and the vertical direction.

300: Adjust the projected image according to the deformation ratio.

Since the optical axis point D is located at the center of the projected image. Therefore, it can be used as a reference point to adjust the projected image before output to avoid distortion or stretching of the projected image.

The adjustment of the projected image is an inverse function of the deformation ratio. For example, when the calculated deformation ratio is 5, the corresponding line in the projected image is compressed to the original one-fifth to maintain the normal display of the projected image.

In some embodiments, as shown in FIG. 9, the projection point and the projected image edge point may include four edge points on the left and right sides and on the upper and lower sides (ie, point B and point C1 and point B1 and point C1). Correspondingly, the distance between the projection point A and the edge point of the projected image may also include a first lateral distance AB and a second lateral distance AC between the projected image edge points formed by the straight line passing through the optical axis point. And a first longitudinal distance AB1 and a second longitudinal distance AC1 between the projection point and the edge point of the projected image formed by the straight line passing through the optical axis point.

As shown in FIG. 3, the deformation ratio can also summarize the deformation ratios in two mutually perpendicular directions, that is, the longitudinal deformation ratio and the lateral deformation ratio corresponding to the elevation angle and the width angle, respectively.

In order to ensure the normal display of the projected image as a whole, it is necessary to obtain a longitudinal deformation ratio and a lateral deformation ratio. In some embodiments, calculating a lateral deformation ratio of the pixel point of the projection image on the projection surface according to the width angle, the projection optical axis length, the first lateral distance, and the second lateral distance, or according to the elevation angle, the projection light The length of the shaft, the first longitudinal distance, and the second longitudinal distance, and calculating the ratio of the longitudinal deformation of the pixel on the projection surface of the projected image

Assuming that the projection surface is perpendicular to the horizontal plane, and the projection optical axis is parallel to the horizontal plane (ie, there is only an angle between the projection optical axis and the projection surface in the horizontal direction), the longitudinal deformation ratio of the pixel point may also be according to the height. The angular and lateral deformation ratios are calculated.

The above calculation method for deriving the longitudinal deformation ratio according to the lateral deformation ratio can reduce the calculation amount of the longitudinal deformation ratio and improve the calculation speed when the assumption is satisfied.

For example, assuming that the projection surface is perpendicular to a horizontal plane, the projection optical axis is parallel to a horizontal plane, the projected image has m pixels in a lateral direction and n pixels in a longitudinal direction:

Since each pixel point is still perpendicular to the horizontal plane in the longitudinal direction, the pixels can be considered to constitute a plurality of similar trapezoids, and the pixel points in the longitudinal direction are equivalent in size. If a ₁ , a ₂ , ..., a _m represents the lateral deformation ratio corresponding to m pixel points in the lateral direction. According to the principle of similar triangles, the longitudinal deformation ratios b ₁ , b ₂ , ..., b _m at the corresponding m pixel points should be:

b ₁ =n×a ₁

b ₂ =n×a ₁ +a ₁ ×tanγ,n×a ₁ +(a ₁ +a ₂ )×tanγ

...

b _m =n×a ₁ +(a ₁ +a ₂ +...+a _m-1 )×tanγ

Where γ is the elevation angle.

Correspondingly, in other embodiments, if the projection optical axis only has an angle between the vertical direction and the projection surface, the longitudinal deformation ratio may be first calculated, and then the longitudinal deformation is performed by a similar calculation method. The ratio calculates the lateral deformation ratio.

In the case that the above assumptions are not met (for example, if the projection surface is not perpendicular to the horizontal plane or the projection optical axis is not parallel to the horizontal, there is an angle between the horizontal direction and the vertical direction), the longitudinal deformation ratio needs to be deformed according to the lateral direction. The method is similarly calculated, that is, the longitudinal deformation ratio of the pixel on the projection surface of the projected image needs to be calculated according to the height angle, the projection optical axis distance, the first longitudinal distance, and the second longitudinal distance.

After the lateral deformation ratio and the longitudinal deformation ratio are calculated, each row of the projected image may be compressed or stretched to a normal display width according to the lateral deformation ratio, and each column of the projected image may be compressed according to the longitudinal deformation ratio. Or stretch to the normal display height. Through such a correction method, the projection image to be corrected is subjected to corresponding deformation processing, so that the projection image finally projected on the projection surface is normally displayed.

The following is an example of the projection correction effect shown in FIG. 5, and the lateral deformation ratio calculation process of the above-described projected image is described in detail. It will be understood by those skilled in the art that in the following embodiments, the width angle, the first lateral distance, and the second lateral distance may be replaced by corresponding height angles, first longitudinal distances, and second longitudinal distances to calculate the vertical direction. Deformation ratio.

As shown in FIG. 5, the acute angle BAC is the width angle of the projection device, and it is assumed that there are 6 pixel points in the lateral direction, and is evenly distributed between the ideal projection surfaces EF.

Since the ideal projection surface EF forms a certain angle with the current projection surface. Therefore, the projected image DC will exhibit a certain degree of tensile deformation in the lateral direction. To calculate the ratio of the tensile deformation, the following calculation is required:

On the one hand, as shown in Fig. 5, the angle α of the width angle is a known amount, α = 2 (α ₁ + α ₂ + α ₃ ), where α ₁ , α ₂ , α ₃ are pixel points 1, pixel points, respectively 2 and the optical path angle of pixel 3.

From the geometric relationship in Figure 6:

L is the length of the projection optical axis AD, and a is the standard width at the time of normal display of the pixel. The value of a can be calculated by the formula (1).

Further, the standard width a of the obtained pixel points is calculated according to the formula (1), and the optical path angles α ₁ , α ₂ , α ₃ can be sequentially solved by the following formula

On the other hand, in a triangular ADC, according to the cosine theorem:

Where AD is the length of the projection optical axis, and AC belongs to the distance between the projection point and the edge point of the projected image. They can each be obtained by the ranging module ranging, and the angle α of the width angle is a known amount. Therefore, DC can be obtained according to the formula (2).

According to the sine theorem:

By calculating the value of the obtained DC by the formula (2), the inclination angle β (ie, the angular ADC) between the projection optical axis and the projection surface can be obtained.

In the triangle surrounded by the pixel point 1, the pixel point 2, and the pixel point 3 and the projection optical axis AD, according to the sine theorem:

Where x represents the width of pixel 1 , y represents the width of pixel 2, and z represents the width of pixel 3 .

The object of the embodiment of the invention is to calculate the deformation ratio. Therefore, the ratio of x to y and the ratio of y to z can be calculated by combining equations (4-1) to (4-3).

After the joint:

According to the above description, it can be seen that in the simultaneous equations (5-1) and (5-2), the unknown amount to be solved is required: the optical path angles (α ₁ , α ₂ , α ₃ ) of the respective pixel points can be Solving by the a value of the formula (1); the tilt angle β between the projection optical axis and the projection surface (ie, the angular ADC) can be solved by the formula (2) and the formula (3).

Therefore, the optical path angle and the tilt angle solved by the equations (1), (2), and (3) can be substituted into the simultaneous equations (5-1) and (5-2) to solve the pixel point 1, the pixel point 2, and the pixel. The ratio of deformation between points 3.

According to the calculation method disclosed in the above embodiments, those skilled in the art can understand that after calculating the corresponding optical path angle of the pixel point and the tilt angle β between the projection optical axis and the projection surface, the deformation of any pixel point can be calculated. Proportion (ie the ratio of x to y and the ratio of y to z). Similarly, the method applying the same principle can be extended to the case where there are n pixel points, and the deformation ratio of any pixel point among the n pixel points is calculated.

In some embodiments, based on the principle of geometric mathematics, the optical path angle corresponding to the pixel point and the tilt angle between the projection optical axis and the projection surface can be calculated by any suitable means under different preconditions. , thereby further calculating the deformation ratio.

It can be understood by those skilled in the art that, although the case where the horizontal direction is 6 pixels is shown in FIG. 5, the idea disclosed in the above embodiment and the same geometric mathematical principle can be further deduced to the pixel point. For n cases. For example, when the number of horizontal pixels is 1080,

In Fig. 5, only the correction process of the projected portion of the projected image in the DC segment is described in detail. According to the idea disclosed in the embodiments of the present invention, the corresponding compression part in the projected image can also be calculated by using the same geometric mathematical principle.

For the stretched portion, the deformation ratio is a positive value greater than one. For the compressed part, the deformation ratio is a positive value between 0-1.

In some embodiments, after calculating the lateral deformation ratios a ₁ , a ₂ , . . . , a _{n of the} projected image and the longitudinal deformation ratios b ₁ , b ₂ , . . . , b _m , they may be integrated into corresponding calibration curves. In order to facilitate the adjustment of the projected image by a computer or a logic operation module.

The calibration curve obtained by the integration can be stored in any suitable storage medium, and the projection device applies the calibration curve to correct the projected image and project the corrected image on the projection surface.

A projection apparatus that performs the projection image correction method described in the above method embodiment can be applied to many different usage scenarios by using the embodiments of the present invention. For example, Figure 6 is one of the usage scenarios.

As shown in FIG. 6, in this usage scenario, the user 10, the projection device 20, and the projection surface 30 are included. The projection device 20 is disposed on the robot and moves at a constant speed along the trajectory z1. The robot uses the projection device 20 to present a projected image for explanation to the user 10 on the projection surface 30.

As shown in FIG. 6, during the movement along the trajectory z1, since the length AD of the projection optical axis is always constant, the projection image provided by the above method embodiment can be repeatedly executed in real time. The correction method implements real-time adjustment of the projected image following the movement of the robot.

With continued reference to FIG. 6, in other usage scenarios, the projection device 20 can also be moved along the trajectory z2. During the movement along the trajectory z2, the length AD of the projection optical axis changes over time. Therefore, the projection device 20 needs to keep the shape and size of the projected image in accordance with its own zoom zoom.

As described above, according to the optical projection principle, the height and width of the projected image are both in direct proportional relationship with the length AD of the projection optical axis. If it is assumed that the length change ratio of the length AD of the projection optical axis at any two moments is p, the projection device 20 can scale the projected image to be corrected to the original

Then, the projection image correction method provided by the above method embodiment is repeatedly executed in real time to realize real-time adjustment of the projection image following the movement of the robot. Of course, it is also possible to adjust the scaling and correction execution order, that is, firstly perform the projection image correction method provided by the above method embodiment, and then scale the projection image.

With continued reference to FIG. 6, in another usage scenario, the projection device 20 may also be located at a fixed position z3. In such a use scenario, the projection device 20 can perform only one operation to acquire a corresponding calibration curve, that is, to keep the projected image from being stretched, deformed, or otherwise distorted during projection, maintaining the viewing experience of the user 10.

In more usage scenarios, the projection device 20 needs to remain in a stable position regardless of whether it is in a moving process. That is, the position of the optical axis point D of the projection optical axis AD needs to be maintained at a stable position. The method of specifically maintaining the projection optical axis at the optical axis point D is well known to those skilled in the art and can be adjusted and determined by the robot according to its trajectory and other suitable data, and will not be described herein.

The projection image correction method provided by the above method embodiment can ensure that the image is not distorted when the projection optical axis does not have to be perpendicular to the wall surface or the screen surface. Further, by real-time correction operation, the projection device can also ensure that the image does not move without distortion during the small-range movement.

This greatly facilitates the installation of the robot with the projection device at any time to display the content on the large screen. On the one hand, it can be easily projected on the side of the image and does not block the owner. On the other hand, it is not allowed in environmental conditions, and it has to be projected from the side at an angle without causing image distortion.

The real-time correction provided by the projection image correction method can also allow the robot to perform a small range of movement during the projection process, such as a more vivid explanation, or move to indicate an item in the picture, or move a small range to complete other tasks while projecting. In order to improve efficiency and so on, a variety of new scenarios can be implemented, which greatly enhances the user experience and meets the user's needs.

FIG. 7 is a projection image correction apparatus according to an embodiment of the present invention. The device includes: a ranging module 100, a calculation module 200, and an adjustment module 300.

The ranging module 100 is configured to acquire a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: a perpendicular line passing through the optical axis point of the projection optical axis The intersection with the edge of the projected image. The calculation module 200 is configured to calculate a deformation ratio of the pixel points of the projection image on the projection surface according to the angle of view, the length of the projection optical axis, and the distance between the projection point and the edge point of the projection image. The adjustment module 300 is configured to adjust the projection image according to the deformation ratio.

As shown in FIG. 9, in the projection device, the projection point and the edge point of the projected image may include four edge points on the left and right sides and the upper and lower sides.

After the distance measuring module 100 acquires the length of the projection optical axis and the distance between the projection point and the edge point of the projected image, the corresponding data is output to the calculation module 200. The calculation module 200 combines some fixed parameters of the projection device, such as the angle of view, to calculate the deformation ratio of the projected image on the projection surface, and the adjustment module 300 acquires the deformation ratio calculated by the calculation module 200, corrects the projection image, and then projects the projection image. On the projection surface.

For example, when the calculation module calculates that the horizontal deformation ratio of a certain line of the projection image on the projection surface is 2, the adjustment module 300 compresses the line to the original one-half, and maintains the normal display of the projection image on the projection surface.

In some embodiments, the adjustment module 300 is further configured to generate a corresponding calibration curve according to the deformation ratio of each pixel point obtained by the calculation module 200, for example, a curve composed of a deformation ratio in a lateral direction and a longitudinal direction. The deformation ratio consists of a curve.

After generating the calibration curve, the adjustment module 300 can use the calibration curve to sequentially correct the projected image and project the corrected projected image onto the projection surface.

In other embodiments, the calculation module 300 may also apply the calculation method provided by the method embodiment above, obtain corresponding data, and calculate the lateral deformation ratio and/or the longitudinal deformation ratio.

For example, under the assumption that the projection plane is perpendicular to the horizontal plane and the projection optical axis is parallel to the horizontal plane, the projection image is calculated according to the width angle, the projection optical axis length, the first lateral distance, and the second lateral distance. a ratio of lateral deformation of the pixel on the projection surface; and then calculating a longitudinal deformation ratio of the pixel on the projection surface according to the height angle and the lateral deformation ratio, or according to the elevation angle, the length of the projection optical axis, and the first vertical direction The distance and the second longitudinal distance are used to calculate a longitudinal deformation ratio of the pixel points of the projection image on the projection surface; and then the lateral deformation ratio of the pixel points of the projection image on the projection surface is calculated according to the width angle and the longitudinal deformation ratio.

FIG. 8 is a schematic structural diagram of hardware of an electronic device according to an embodiment of the present invention. The electronic device can be any suitable projection device or a robot provided with a projection device. The robot may also have one or more power devices for driving the robot to move along a particular trajectory.

As shown in FIG. 8, the device includes: one or more processors 810 and a memory 820, and one processor 810 is taken as an example in FIG.

The processor 810 and the memory 820 may be connected by a bus or other means, and the bus connection is taken as an example in FIG.

The memory 820 is a non-volatile computer readable storage medium and can be used to store non- The volatile software program, the non-volatile computer executable program, and the module, such as the program instruction/module corresponding to the projection image correction method in the embodiment of the present invention (for example, the ranging module 100 shown in FIG. 7 , the calculation module 200 And an adjustment module 300). The processor 810 executes various functional applications of the server and data processing by executing non-volatile software programs, instructions, and modules stored in the memory 820, that is, implementing the projection image correction method of the above method embodiment.

The memory 820 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application required for at least one function; the storage data area may store data created according to use of the projection image correction device, and the like. Moreover, memory 820 can include high speed random access memory, and can also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, memory 820 can optionally include memory remotely disposed relative to processor 820, which can be coupled to the projected image correction device over a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The one or more modules are stored in the memory 820, and when executed by the one or more processors 810, perform a projected image correction method in any of the above method embodiments.

A person skilled in the art should further appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, in order to clearly illustrate hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application. The computer software can be stored in a computer readable storage medium, which, when executed, can include the flow of an embodiment of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only storage memory, or a random storage memory.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformations made by the description of the invention and the drawings are directly or indirectly applied to other related technologies. The fields are all included in the scope of patent protection of the present invention.

Claims (25)

1. A projection image correction method, comprising:

   Obtaining a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: an intersection of a perpendicular line passing through the optical axis of the projection optical axis and an edge of the projected image;

   Calculating a deformation ratio of the pixel points of the projection image on the projection surface according to the angle of view, the length of the projection optical axis, and the distance between the projection point and the edge point of the projection image;

   The projected image is adjusted according to the deformation ratio.
2. The method according to claim 1, wherein the distance between the projection point and the edge point of the projected image comprises: a first lateral distance between the projection point and the edge point of the projected image formed by a straight line passing through the optical axis point. And a second lateral distance, a first longitudinal distance and a second longitudinal distance between the projected point and the edge point of the projected image formed by the straight line passing perpendicular to the optical axis point.
3. The method according to claim 2, wherein the angle of view comprises: a width angle in a horizontal direction and an elevation angle in a vertical direction;

   The projection surface is perpendicular to a horizontal plane, and the projection optical axis is parallel to a horizontal plane.

   The calculating the deformation ratio of the pixel points on the projection surface of the projection image specifically includes: calculating a lateral deformation of the pixel of the projection image on the projection surface according to the width angle, the length of the projection optical axis, the first lateral distance, and the second lateral distance proportion;

   According to the height angle and the lateral deformation ratio, the longitudinal deformation ratio of the pixel points of the projected image on the projection surface is calculated.
4. The method according to claim 3, wherein the projected image has m pixels in a lateral direction and n pixels in a longitudinal direction, and m pixels corresponding to the lateral direction are calculated by the following formula Longitudinal deformation ratio:

   b ₁ =n×a ₁

   b ₂ =n×a ₁ +a ₁ ×tanγ

   b ₃ =n×a ₁ +(a ₁ +a ₂ )×tanγ

   ······

   b _m =n×a ₁ +(a ₁ +a ₂ +...+a _m-1 )×tanγ

   Wherein a ₁ , a ₂ , . . . , a _m is a lateral deformation ratio corresponding to m pixel points in the lateral direction, and γ is the elevation angle, and b ₁ , b ₂ , b ₃ , . . . , b _m are The longitudinal deformation ratio of the m pixel points in the lateral direction.
5. The method according to claim 2, wherein the angle of view comprises: a width angle in a horizontal direction and a height angle in a vertical direction; and calculating a deformation ratio of the pixel points on the projection surface of the projection image comprises: Calculating a longitudinal deformation ratio of the pixel point of the projection image on the projection surface, the height angle, the length of the projection optical axis, the first longitudinal distance, and the second longitudinal distance;

   Calculating a lateral deformation ratio of the pixel points of the projected image on the projection surface according to the width angle and the longitudinal deformation ratio.
6. The method according to claim 3 or 5, wherein the adjusting the projection image according to the deformation ratio comprises:

   Compressing or stretching each line of the projected image to a normal display width according to the lateral deformation ratio;

   Each column of the projected image is compressed or stretched to a normal display height according to the longitudinal deformation ratio.
7. The method according to claim 3 or 5, wherein the calculating the ratio of the lateral deformation of the pixel points on the projection surface of the projection image comprises:

   Calculating the optical path angle of the pixel according to the width angle;

   Calculating a first angle between the projection optical axis and the projection surface according to the width angle, the length of the projection optical axis, and the distance between the edge of the projected image and the projection point;

   According to the optical path angle and the first angle, the lateral deformation ratio of the pixel points is calculated.
8. The method according to claim 7, wherein the optical path angle of the lateral deformation ratio is specifically calculated by the following method:

   Calculate the standard width of the pixel by the following formula:

   

   among them,

   

   Is half of the width angle; a is the standard width of the pixel, n is the number of pixels included in each row in the projected image, and L is the length of the projection optical axis;

   The optical path angle corresponding to each pixel point is sequentially calculated by the following formula:

   

   α _n is the optical path angle corresponding to the nth pixel point.
9. The method according to claim 7, wherein the first angle of the lateral deformation ratio is specifically calculated by the following method:

   Calculate the distance between the optical axis point of the projected optical axis and the edge point of the projected image by the following formula:

   

   Where DC is the distance between the optical axis point of the projection optical axis on the projection surface and the edge point of the projected image, L is the length of the projection optical axis, and L ₁ is the distance between the projection point and the edge point of the projected image.

   

   Half of the width angle;

   According to the distance between the optical axis point and the edge point of the projected image, the first angle is calculated by the following formula:

   

   Where β is the first angle.
10. The method according to claim 7, wherein said lateral deformation ratio is calculated by the following formula:

    

    Where y is the width of the n-1th pixel point; z is the width of the nth pixel point;

    

    For the lateral deformation ratio, α _n is the optical path angle of the nth pixel.
11. The method according to any one of claims 1 to 10, wherein the adjusting the projection image according to the deformation ratio comprises:

    Generating a corresponding calibration curve according to the deformation ratio;

    Using the calibration curve, correspondingly adjusting a shape size of the projected image;

    Projecting the adjusted projected image onto the projection surface.
12. A projection image correction device, comprising:

    a ranging module, configured to acquire a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: an intersection of a perpendicular line passing through the optical axis of the projection optical axis and an edge of the projection image;

    a calculation module, configured to calculate a deformation ratio of the pixel of the projection image on the projection surface according to the angle of view, the length of the projection optical axis, and the distance between the projection point and the edge point of the projection image;

    And an adjustment module, configured to adjust the projected image according to the deformation ratio.
13. The apparatus according to claim 12, wherein the distance between the projection point and the edge point of the projected image comprises: a first lateral distance between the projected point and the edge point of the projected image formed by the straight line passing through the optical axis point horizontally And a second lateral distance, a first longitudinal distance and a second longitudinal distance between the projected point and the edge point of the projected image formed by the straight line passing perpendicular to the optical axis point.
14. The apparatus according to claim 13, wherein said angle of view comprises: a width angle in a horizontal direction and an elevation angle in a vertical direction;

    The projection surface is perpendicular to a horizontal plane, and the projection optical axis is parallel to a horizontal plane.

    The calculation module is specifically configured to: calculate a lateral deformation ratio of the pixel of the projection image on the projection surface according to the width angle, the projection optical axis length, the first lateral distance, and the second lateral distance.
15. The apparatus according to claim 14, wherein said projected image has m pixels in a lateral direction and n pixels in a longitudinal direction, and m pixels corresponding to said lateral direction are calculated by an equation Longitudinal deformation ratio;

    The calculation module is specifically configured to calculate m in the lateral direction by using the following formula The ratio of the longitudinal deformation corresponding to the pixel:

    b ₁ =n×a ₁

    b ₂ =n×a ₁ +a ₁ ×tanγ

    b ₃ =n×a ₁ +(a ₁ +a ₂ )×tanγ

    ······

    b _m =n×a ₁ +(a ₁ +a ₂ +...+a _m-1 )×tanγ

    Wherein a ₁ , a ₂ , . . . , a _m is a lateral deformation ratio corresponding to m pixel points in the lateral direction, and γ is the elevation angle, and b ₁ , b ₂ , b ₃ , . . . , b _m are The longitudinal deformation ratio of the m pixel points in the lateral direction.
16. The apparatus according to claim 13, wherein said angle of view comprises: a width angle in a horizontal direction and an elevation angle in a vertical direction;

    The calculating module is specifically configured to: calculate a longitudinal deformation ratio of a pixel of the projection image on the projection surface according to the height angle, the length of the projection optical axis, the first longitudinal distance, and the second longitudinal distance;

    Calculating a lateral deformation ratio of the pixel points of the projected image on the projection surface according to the width angle and the longitudinal deformation ratio.
17. The device according to claim 14 or 16, wherein the adjustment module is specifically configured to:

    Compressing or stretching each line of the projected image to a normal display width according to the lateral deformation ratio;

    Each column of the projected image is compressed or stretched to a normal display height according to the longitudinal deformation ratio.
18. The device according to claim 14 or 16, wherein the calculation module is specifically configured to:

    Calculating the optical path angle of the pixel according to the width angle;

    Calculating a first angle between the projection optical axis and the projection surface according to the width angle, the length of the projection optical axis, and the distance between the edge of the projected image and the projection point;

    According to the optical path angle and the first angle, the lateral deformation ratio of the pixel points is calculated.
19. The device according to claim 17, wherein the calculation module is specifically configured to:

    Calculate the standard width of the pixel by the following formula:

    

    among them,

    

    Is half of the width angle; a is the standard width of the pixel, n is the number of pixels included in each row in the projected image, and L is the length of the projection optical axis;

    The optical path angle corresponding to each pixel point is sequentially calculated by the following formula:

    

    α _n is the optical path angle corresponding to the nth pixel point.
20. The device according to claim 19, wherein the calculation module is specifically configured to:

    The first angle of the lateral deformation ratio is specifically calculated by the following method:

    Calculate the distance between the optical axis point of the projected optical axis and the edge point of the projected image by the following formula:

    

    Where DC is the distance between the optical axis point of the projection optical axis on the projection surface and the edge point of the projected image, L is the length of the projection optical axis, and L ₁ is the distance between the projection point and the edge point of the projected image.

    

    Half of the width angle;

    According to the distance between the optical axis point and the edge point of the projected image, the first angle is calculated by the following formula:

    

    Where β is the first angle.
21. The device according to claim 18, wherein the calculation module is specifically configured to: calculate the deformation ratio by using the following formula:

    

    Where y is the width of the n-1th pixel point; z is the width of the nth pixel point;

    

    For the lateral deformation ratio, α _n is the optical path angle of the nth pixel.
22. The apparatus according to any one of claims 12 to 21, wherein the adjustment module is further configured to: generate a corresponding calibration curve according to the deformation ratio; and use the calibration curve to adjust the projection image correspondingly Shape size; the adjusted projected image is projected onto the projection surface.
23. A robot comprising at least one projection device, a processor, and a ranging unit;

    The ranging unit is configured to acquire a length of the projection optical axis and a distance between the projection point and an edge point of the projection image; the edge point of the projection image is: an intersection of a perpendicular line passing through the optical axis point of the projection optical axis and an edge of the projection image;

    The processor is configured to calculate a deformation ratio of a pixel of the projection image on the projection surface according to the length of the projection optical axis acquired by the ranging unit, the distance between the projection point and the edge point of the projection image, and the angle of view of the projection device, and according to The deformation ratio is adjusted to adjust a projection image;

    The projection device is configured to project the adjusted projection image onto the projection surface.
24. The robot according to claim 23, wherein said robot further comprises a power unit;

    The power device drives the robot to move during projection of the projection device; the ranging module acquires the length of the projection optical axis and the distance between the projection point and the edge point of the projected image in real time;

    The processor is further configured to adjust the projection image according to the length of the projection optical axis and the change of the distance between the projection point and the edge point of the projection image;

    The projection device is configured to project the adjusted projection image onto the projection surface.
25. A computer program product comprising a software code portion, characterized in that the software code portion is configured to perform the method steps of any one of claims 1-11 when run in a memory of a computer.

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