Projection equipment, projection picture correction method and storage medium

Abstract

The invention relates to projection equipment, a projection picture correction method and a storage medium. The method comprises the following steps: collecting first coordinates and second coordinates of four vertexes in a ray machine coordinate system before and after keystone correction; calculating a first perspective transformation matrix and a second perspective transformation matrix according to the first coordinate and the second coordinate; respectively converting the first coordinate and the second coordinate into a third coordinate and a fourth coordinate in a wall coordinate system; calculating a fifth coordinate of each vertex in the wall coordinate system after the picture adjustment operation; using a second perspective change matrix to convert the fifth coordinate of each vertex into a sixth coordinate under a ray machine coordinate system; and adjusting the parameters of the ray machine, so that the projection coordinates of the adjusted vertexes in the ray machine coordinate system are the sixth coordinates of the vertexes. According to the invention, rotation, zooming and translation operations can be carried out while the shape of a projection picture is kept.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection device, a projection picture correction method and a storage medium. Background Art

[0002] With the development of projection technology, projection has gradually become a widely used multimedia display method.

[0003] When using a projector, poor visual effects are often caused by limitations of the use environment (such as: the projector is placed on a non-horizontal plane, there are obstructions in the projection image, etc.). Therefore, existing projectors generally provide keystone correction and obstacle avoidance functions to obtain better visual effects. However, in actual applications, if there is a large error in the keystone correction result, causing the image to tilt, or the obstacle avoidance function fails to avoid obstacles, it is necessary to use operations such as image rotation, image zooming, and image translation to adjust the projection image to obtain better visual effects.

[0004] However, the current functions of image rotation, image scaling and image translation are achieved by adjusting the projection coordinates on the optical coordinate system. But in order to keep the shape of the projected image on the wall coordinate system as a rectangle, trapezoidal correction is usually performed to convert the projection coordinates on the optical coordinate system into a trapezoid. At this time, if the image is rotated, scaled and translated directly on the optical coordinate system to change the projection coordinates, the shape of the projection on the wall coordinate system will be deformed, making the user experience worse. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a projection device, a projection picture correction method and a storage medium.

[0006] The specific plan is as follows:

[0007] A projection image correction method comprises the following steps:

[0008] S1: The projections of the four vertices in the image in the optical machine coordinate system when the optical machine is at the maximum image are taken as the first coordinates of each vertex;

[0009] S2: collecting the projection coordinates of the four vertices in the optical machine coordinate system after performing trapezoidal correction on the optical machine projection image as the second coordinates of each vertex;

[0010] S3: According to the first coordinates and the second coordinates of the four vertices, respectively calculate a first perspective transformation matrix from the first coordinates to the second coordinates and a second perspective transformation matrix from the second coordinates to the first coordinates;

[0011] S4: using the third perspective change matrix transformed from the optical-mechanical coordinate system to the wall coordinate system, converting the first coordinate of each vertex into a projection coordinate in the wall coordinate system as the third coordinate of each vertex, and converting the second coordinate of each vertex into a projection coordinate in the wall coordinate system as the fourth coordinate of each vertex;

[0012] S5: After the keystone correction, the optical machine projection screen is adjusted, and the projection coordinates of each vertex in the wall coordinate system after the operation are calculated as the fifth coordinates of each vertex;

[0013] S6: using the second perspective transformation matrix, converting the fifth coordinate of each vertex into a projection coordinate in the optical-mechanical coordinate system as the sixth coordinate of each vertex;

[0014] S7: Adjust the parameters of the optical machine so that the projection coordinates of each vertex in the optical machine coordinate system after adjustment are the sixth coordinates thereof.

[0015] Furthermore, in step S4, when calculating the fourth coordinate of each vertex, the first perspective transformation matrix is ​​used to convert the third coordinate of each vertex into a projection coordinate in the wall coordinate system as the fourth coordinate of each vertex.

[0016] Furthermore, the picture adjustment operation may include one or more of rotation, scaling and translation.

[0017] A projection device, wherein the projection device uses the above method of the embodiment of the present invention to calibrate a projection image.

[0018] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described above in an embodiment of the present invention are implemented.

[0019] The present invention adopts the above technical solution, and can perform rotation, scaling and translation operations while maintaining the shape of the projection image. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a flow chart of a method according to a first embodiment of the present invention.

[0021] Figure 2 Shown is a schematic diagram of a screen formed by coordinates in two coordinate systems in this embodiment.

[0022] Figure 3 It is a first schematic diagram of the picture surrounded by the coordinates in the two coordinate systems before and after the picture adjustment operation in this embodiment.

[0023] Figure 4 It is a second schematic diagram of the picture surrounded by the coordinates in the two coordinate systems before and after the picture adjustment operation in this embodiment. DETAILED DESCRIPTION

[0024] To further illustrate various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementations and advantages of the present invention.

[0025] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0026] Embodiment 1:

[0027] The embodiment of the present invention provides a projection image correction method, such as Figure 1 As shown, the method comprises the following steps:

[0028] S1: The projection of the four vertices in the image in the optical machine coordinate system when the acquisition optical machine is at the maximum image is used as the first coordinate S of each vertex max .

[0029] S2: Collect the projection coordinates of the four vertices in the optical machine coordinate system after performing trapezoidal correction on the optical machine projection image as the second coordinates S of each vertex trap .

[0030] Steps S1 and S2 correspond to before and after trapezoidal correction, respectively.

[0031] S3: According to the first coordinates S of the four vertices max and the second coordinate S trap , respectively calculate a first perspective transformation matrix M1 for transforming from the first coordinates to the second coordinates and a second perspective transformation matrix M2 for transforming from the second coordinates to the first coordinates.

[0032] The first perspective transformation matrix M1 and the second perspective transformation matrix M2 can both be expressed as:

[0033]

[0034] Among them, a 11 、a 21 、a 31 、a 12 、a 22 、a 32 Indicates the coefficient of rotation and scaling, a 13 、a 23 、a 33 Represents the translation amount, (x, y) is the coordinate before perspective transformation.

[0035] The coordinates (x′, y′) after perspective transformation are:

[0036]

[0037] S4: Use the third perspective change matrix M3 that transforms the optical machine coordinate system into the wall coordinate system to transform the first coordinate S of each vertex max Convert to the projection coordinates in the wall coordinate system as the third coordinate W of each vertex max , and at the same time, the second coordinate S of each vertex trap Convert to the projection coordinates in the wall coordinate system as the fourth coordinate W of each vertex trap .

[0038] Furthermore, in another embodiment, the fourth coordinate W of each vertex can be calculated by the following method: trap , that is, using the first perspective transformation matrix M1, the third coordinate W of each vertex max Convert to the projection coordinates in the wall coordinate system as the fourth coordinate W of each vertex trap .

[0039] The third perspective change matrix M3 for perspective transformation of the optical-mechanical coordinate system into the wall coordinate system can be obtained by the projection coordinates of the points in the projection picture in the wall coordinate system and the projection coordinates in the optical-mechanical coordinate system when the optical-mechanical system is projected onto the wall.

[0040] S5: After the trapezoidal correction, the optical machine projection screen is adjusted, and the projection coordinates of each vertex in the wall coordinate system after the operation are calculated as the fifth coordinate W of each vertex trap_rst .

[0041] The picture adjustment operation may include one or more of rotation, scaling and translation. trap_rst In the calculation of trap , calculate the fifth coordinate W according to the rotation angle, scaling ratio, displacement, etc. of the screen adjustment operation trap_rst .

[0042] S6: Use the second perspective transformation matrix M2 to transform the fifth coordinate W of each vertex trap_rst Convert to the projection coordinates in the optical-mechanical coordinate system as the sixth coordinate S of each vertex trap_rst .

[0043] S7: Adjust the parameters of the optical machine so that the projection coordinates of each vertex in the optical machine coordinate system after adjustment are the sixth coordinates S trap_rst .

[0044] Figure 2 The middle left picture shows the first coordinate S of the optical machine coordinate system when the optical machine is at the maximum image size. max and the third coordinate W in the wall coordinate system maxThe surrounded screen. Figure 2 The middle right picture shows the second coordinate S in the optical machine coordinate system after trapezoidal correction. trap and the fourth coordinate W in the wall coordinate system trap The surrounded screen.

[0045] Figure 3 The second coordinate S in the optical-mechanical coordinate system after trapezoidal correction is shown. trap The sixth coordinate S in the optical-mechanical coordinate system is obtained after the enclosed image is adjusted. trap_rst , and its corresponding coordinate in the wall coordinate system is the fifth coordinate W trap_rst . It can be seen that the fifth coordinate W trap_rst The shape of the screen and the fourth coordinate W trap The shape of the enclosed image is not consistent and is obviously deformed. Therefore, directly moving the projection coordinates in the optical machine coordinate system will cause the projection shape projected on the wall coordinate system to deform.

[0046] Figure 4 The fourth coordinate W in the wall coordinate system after trapezoidal correction is shown. trap The fifth coordinate W in the wall coordinate system is obtained after the enclosed image is adjusted. trap_rst , and its corresponding coordinate in the optical-mechanical coordinate system is S trap_rst . It can be seen that the fifth coordinate W trap_rst The shape of the screen and the fourth coordinate W trap The enclosed images are all of the same shape, rectangular, and have not been deformed.

[0047] from Figure 3 and Figure 4 It can be seen from the comparison that the operation in the optical machine coordinate system will cause the projection image in the wall coordinate system to deform, resulting in a poor projection perception. However, using the method of this embodiment, the rotation, scaling and translation operations can be performed while maintaining the shape of the projection image.

[0048] Embodiment 2:

[0049] The present invention further provides a projection device, wherein the projection device uses the above method of the first embodiment of the present invention to perform projection picture correction.

[0050] Embodiment three:

[0051] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method in the embodiment of the present invention are implemented.

[0052] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A projection image correction method, characterized in that: The following steps are involved: S1: The projections of the four vertices in the image in the optical machine coordinate system when the optical machine is at the maximum image are taken as the first coordinates of each vertex; S2: collecting the projection coordinates of the four vertices in the optical machine coordinate system after performing trapezoidal correction on the optical machine projection image as the second coordinates of each vertex; S3: According to the first coordinates and the second coordinates of the four vertices, respectively calculate a first perspective transformation matrix from the first coordinates to the second coordinates and a second perspective transformation matrix from the second coordinates to the first coordinates; S4: using the third perspective change matrix transformed from the optical-mechanical coordinate system to the wall coordinate system, converting the first coordinate of each vertex into a projection coordinate in the wall coordinate system as the third coordinate of each vertex, and converting the second coordinate of each vertex into a projection coordinate in the wall coordinate system as the fourth coordinate of each vertex; S5: After the keystone correction, the optical machine projection screen is adjusted, and the projection coordinates of each vertex in the wall coordinate system after the operation are calculated as the fifth coordinates of each vertex; S6: using the second perspective transformation matrix, converting the fifth coordinate of each vertex into a projection coordinate in the optical-mechanical coordinate system as the sixth coordinate of each vertex; S7: Adjust the parameters of the optical machine so that the projection coordinates of each vertex in the optical machine coordinate system after adjustment are the sixth coordinates thereof.

2. The projection image correction method according to claim 1, characterized in that: In step S4, when calculating the fourth coordinate of each vertex, the first perspective transformation matrix is ​​used to convert the third coordinate of each vertex into a projection coordinate in the wall coordinate system as the fourth coordinate of each vertex.

3. The projection image correction method according to claim 1, characterized in that: The picture adjustment operation may include one or more of rotation, scaling, and translation.

4. A projection device, characterized in that: The projection device uses the method as described in any one of claims 1 to 3 to perform projection picture correction.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 3 are implemented.

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