Optical machine off-axis proportional measurement method and device and projection equipment

Abstract

The application relates to a light machine off-axis proportion measurement method and device and a projection equipment. The method comprises the following steps: acquiring a projection picture image, wherein the projection picture image comprises a first image area corresponding to a first projection picture and a second image area corresponding to a second projection picture, the first projection picture is generated by a light machine on a projection plane, and the second projection picture is generated by an auxiliary positioning device on the projection plane; performing a projection transformation on second image position information of the second image area according to projection transformation relationship information between first projection position information of the first projection picture and first image position information of the first image area, to obtain second projection position information of the second projection picture; and measuring an off-axis proportion of the light machine according to relative installation dimensions between the light machine and the auxiliary positioning device, the first projection position information and the second projection position information. The method can improve the off-axis proportion measurement precision of the light machine.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection technology, in particular to a light machine off-axis proportion measurement method and device and a projection equipment. BACKGROUND

[0002] With the development of projection technology, projection correction technology appears, which can correct irregularly shaped projection pictures to make them return to normally shaped projection pictures. The projection correction technology depends on the off-axis proportion of a light machine.

[0003] In the traditional technology, the off-axis proportion of a light machine is equal to the distance from the center of a projection picture to the center of an optical axis divided by half of the width of the projection picture, referring to Figure 1 When measuring the off-axis proportion of a light machine, the width of the projection picture B and the distance A from the lower edge of the projection picture to the center of the optical axis are usually measured manually, and then the off-axis proportion of the light machine can be calculated according to A and B.

[0004] However, since the optical axis of the light machine is invisible, and the distance A is measured with the optical axis of the light machine as the measurement reference, the accuracy of the manually measured distance A is not high, thereby affecting the measurement accuracy of the off-axis proportion of the light machine. SUMMARY

[0005] Therefore, it is necessary to provide a light machine off-axis proportion measurement method, device and projection equipment capable of improving the measurement accuracy of the off-axis proportion of the light machine to solve the above technical problems.

[0006] In a first aspect, the present application provides a light machine off-axis proportion measurement method. The method comprises:

[0007] obtaining a projection picture image captured by a camera, wherein the projection picture image comprises a first image area corresponding to a first projection picture and a second image area corresponding to a second projection picture, the first projection picture is generated by a light machine on a projection plane, and the second projection picture is generated by an auxiliary positioning device on the projection plane;

[0008] projectively transforming second image position information of the second image area according to projection transformation relationship information between first projection position information of the first projection picture and first image position information of the first image area, to obtain second projection position information of the second projection picture;

[0009] measuring the off-axis proportion of the light machine according to relative installation dimensions between the light machine and the auxiliary positioning device, the first projection position information and the second projection position information.

[0010] In one embodiment, measuring the off-axis ratio of the optical engine based on the relative mounting dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information includes:

[0011] Based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimension, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimension is used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine is determined.

[0012] In one embodiment, measuring the first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device based on the first projection position information and the second projection position information includes:

[0013] Based on the first projection position information, the center position of the first projected image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0014] In one embodiment, the second projected image includes a horizontal line laser projection; determining the first relative distance based on the first center position information and the second projection position information includes:

[0015] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0016] In one embodiment, the second projected image includes structured light projection; determining the first relative distance based on the first center position information and the second projection position information includes:

[0017] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0018] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; the step of performing a projective transformation on the second image position information of the second image region based on the projective transformation relationship information between the first projection position information of the first projected image and the first image position information of the first image region to obtain the second projection position information of the second projected image includes:

[0019] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; the projective transformation matrix is ​​determined based on the first projection position information and the first image position information; the projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0020] In one embodiment, after the step of measuring the off-axis ratio of the optical engine based on the relative mounting dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the method further includes:

[0021] The resolution of the projected image and the projection ratio of the optical engine are obtained; the projected image is corrected based on the resolution, the projection ratio, and the off-axis ratio of the optical engine.

[0022] Secondly, this application also provides an optomechanical off-axis ratio measuring device. The device includes:

[0023] An image acquisition module is used to acquire a projected image captured by a camera. The projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane.

[0024] The projection transformation module is used to perform a projection transformation on the second image position information of the second image region based on the projection transformation relationship information between the first projection position information of the first projection image and the first image position information of the first image region, so as to obtain the second projection position information of the second projection image.

[0025] The measurement module is used to measure the off-axis ratio of the optical engine based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information.

[0026] Thirdly, this application also provides a projection device. The projection device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0027] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0028] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0029] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0030] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0031] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0032] The aforementioned method, apparatus, and projection device for measuring the off-axis ratio of an optical engine acquire a projected image captured by a camera. This projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by the optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the same projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. This allows for accurate acquisition of the second projection position information of the second projected image using projective transformation, thereby enabling the measurement of the second projection position information of the second projected image based on the optical engine... The relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information are used to measure the off-axis ratio of the optical engine. Since the relative installation dimensions determine the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device, the off-axis ratio of the optical engine can be measured indirectly by means of the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device, the first projection position information, and the second projection position information. During the entire measurement process, the relative installation dimensions, the first projection position information, and the second projection position information do not need to be measured with the optical axis as the measurement reference. Therefore, the measurement accuracy of the first projection position information, the second projection position information, and the relative installation dimensions can be guaranteed, thereby ensuring the measurement accuracy of the off-axis ratio of the optical engine. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the principle of optical-mechanical off-axis ratio measurement in traditional techniques.

[0034] Figure 2 This is a flowchart illustrating the method for measuring the optical-mechanical off-axis ratio in one embodiment;

[0035] Figure 3This is a schematic diagram of a camera capturing a projected image in one embodiment;

[0036] Figure 4 This is a flowchart illustrating the method for measuring the optical-mechanical off-axis ratio in another embodiment;

[0037] Figure 5 This is a schematic diagram illustrating the principle of using an auxiliary positioning device to measure the optical-mechanical off-axis ratio in one embodiment.

[0038] Figure 6 This is a structural block diagram of an optomechanical off-axis ratio measuring device in one embodiment;

[0039] Figure 7 This is an internal structural diagram of a projection device in one embodiment. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0041] The method for measuring the off-axis ratio of the optical engine in this application is applied to a projection device, which includes a camera, an optical engine, and a projection screen. This application also includes an auxiliary positioning device, which can be part of the projection device itself or an additional device installed outside the projection device. The optical engine can project a first projection image on the projection screen, and the auxiliary positioning device can generate a second projection image on the projection screen to assist in measuring the off-axis ratio of the optical engine.

[0042] In one embodiment, such as Figure 2 As shown, a method for measuring the off-axis ratio of an optical engine is provided. Taking the application of this method to a projection device as an example, the method includes the following steps:

[0043] Step 202: Obtain the projected image captured by the camera. The projected image includes a first image area corresponding to the first projected image and a second image area corresponding to the second projected image. The first projected image is generated by the optical engine projecting onto the projection plane, and the second projected image is generated by the auxiliary positioning device projecting onto the projection plane.

[0044] The optical engine is used to project a first projected image onto the projection plane, and the auxiliary positioning device is used to project a second projected image onto the projection plane. The projection plane is the plane where the projection screen is located. The camera can be a camera built into the projection device and is used to capture images of the projected image onto the projection plane. The projected image includes at least a first image area corresponding to the first projected image and a second image area corresponding to the second projected image.

[0045] As an example, the auxiliary positioning device can be a line laser emitting device, used to emit a horizontal line laser. The corresponding second projection image presented on the projection plane is the image projected by the line laser. At this time, the optical axis of the auxiliary positioning device is located in the horizontal plane where the line laser projection is located.

[0046] As an example, the auxiliary positioning device can be a structured light emitting device for emitting structured light, and the second projected image presented on the projection plane is the image of the structured light projection. At this time, the optical axis of the auxiliary positioning device is perpendicular to the center position of the structured light projection, which can be the geometric center of the structured light projection.

[0047] As an example, structured light projection is a projection with a preset regular shape, the purpose of which is to facilitate the determination of the center position of the structured light projection. For example, structured light projection can be a rectangular projection or a circular projection.

[0048] Step 204: Based on the projective transformation relationship between the first projection position information of the first projection image and the first image position information of the first image region, perform a projective transformation on the second image position information of the second image region to obtain the second projection position information of the second projection image.

[0049] The first projection position information can be the coordinates of key points in the first projected image on the projection plane. For example, if the first projected image is a rectangular image, then the first projection position information can be the coordinates of the four vertices of the rectangular image. The second projection position information can be the coordinates of key points in the second projected image on the projection plane. For example, if the second projected image is a line laser projection, then the first projection position information can be the coordinates of multiple sampling points on the line laser projection. The first image position information is the coordinates of key points in the first image region of the captured image. For example, if the first projected image is a rectangular image, then the first image region can be a rectangular image region, and thus the first image position information is the coordinates of the four vertices of the rectangular image region. The second image position information is the coordinates of key points in the second image region of the captured image. For example, if the second projected image is a line laser projection, then the second image region can be a line laser projection image, and thus the second image position information is the coordinates of multiple sampling points of the line laser projection in the line image.

[0050] Additionally, it should be noted that the points on the projection plane and the points on the camera's image satisfy the projective transformation relationship, also known as the homography transformation relationship. The projective transformation is used to map a point on one projective plane to another projective plane and to map a straight line to a straight line, thus preserving the line.

[0051] As an example, the projective transformation relationship information can be the projective transformation matrix. The formula for the projective transformation relationship between points on the projection plane and points on the camera's image is as follows:

[0052]

[0053] Where X2 is the coordinate of a point on the projection plane, X1 is the coordinate of a point on the camera's captured image, and H is the projective transformation matrix.

[0054] As an example, step 204 includes: obtaining first projection position information of the first projection image; performing key point position recognition on the projection image to obtain first image position information of the first image region and second image position information of the second image region; and performing projective transformation on the second image position information according to the projective transformation matrix between the first projection position information and the first image position information to obtain second projection position information of the second projection image on the projection plane.

[0055] Step 206: Measure the off-axis ratio of the optical engine based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information.

[0056] The relative installation dimension can be the vertical distance between the installation positions of the optical engine and the auxiliary positioning device. This relative installation dimension can be used to characterize the vertical distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device. After the optical engine and the auxiliary positioning device simultaneously project onto the projection plane to generate a first projection plane and a second projection plane, the relative distance from the center of the first projection image to the center of the second projection plane can be determined based on the first projection position information of the first projection plane and the projection position information of the second projection plane. The center of the second projection plane is the optical axis center of the auxiliary positioning device. Therefore, by using the relative installation dimension and the relative distance from the center of the first projection image to the center of the second projection plane, the relative distance from the center of the first projection image to the optical axis center of the optical engine can be determined. Finally, by using the relative distance from the center of the first projection image to the optical axis center of the optical engine and the height of the first projection image, the off-axis ratio of the optical engine can be determined.

[0057] As an example, the mounting positions of the optical engine and the auxiliary positioning device can be fixed by structural components to ensure that the relative mounting dimensions do not change, thereby ensuring that the relative mounting dimensions of each optical engine are basically consistent. In this way, when measuring the off-axis ratio of multiple optical engines, it is not necessary to measure the relative mounting dimensions between each optical engine and the auxiliary positioning device. These relative mounting dimensions can be directly recorded in the instruction manual of the optical engine, thus improving the efficiency of batch measurement of the off-axis ratio of optical engines.

[0058] As an example, refer toFigure 3 , Figure 3 This is a schematic diagram of a camera capturing a projected image in one embodiment, where the positioning sensor is an auxiliary positioning device, t0 is the relative installation dimension between the auxiliary positioning device and the optical engine, and abcd is the first image area. Figure 3 The line laser shown is the image area captured by the line laser projection, i.e., the second image area. Figure 3 The structured light shown is the image area captured by the structured light projection, i.e., the second image area. Therefore, in this embodiment, the auxiliary positioning device can selectively generate line laser projection or structured light projection on the projection screen.

[0059] As an example, step 206 includes: measuring a first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device based on the first projection position information and the second projection position information; measuring a second relative distance from the center of the first projected image to the optical axis center of the optical engine based on the first relative distance and the relative installation dimensions; and calculating the off-axis ratio of the optical engine based on the second relative matrix and the image height of the first projected image.

[0060] As an example, the formula for calculating the off-axis ratio of an optical engine is as follows:

[0061] offset = [D / (B / 2)] * 100%

[0062] Where offset is the off-axis ratio of the optical engine, D is the second relative distance from the center of the first projected image to the optical axis center of the optical engine, and B is the image height of the first projected image.

[0063] As an example, after the optical engine rotates in the vertical or horizontal direction, the projected image can be corrected by using the measured optical engine off-axis ratio.

[0064] In the aforementioned method for measuring the off-axis ratio of an optical engine, a projected image captured by a camera is acquired. This projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by the optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projected position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projected position information of the second projected image. This allows for accurate acquisition of the second projected position information of the second projected image using the projective transformation, thereby enabling accurate measurement based on the optical engine and the auxiliary positioning device. The relative installation dimensions, first projection position information, and second projection position information are used to measure the off-axis ratio of the optical engine. Since the relative installation dimensions determine the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device, the off-axis ratio of the optical engine can be measured indirectly by means of the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device, the first projection position information, and the second projection position information. During the entire measurement process, the relative installation dimensions, the first projection position information, and the second projection position information do not need to be measured with the optical axis as the measurement reference. Therefore, the measurement accuracy of the first projection position information, the second projection position information, and the relative installation dimensions can be guaranteed, thereby ensuring the measurement accuracy of the off-axis ratio of the optical engine.

[0065] In one embodiment, such as Figure 4 As shown, based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured, including:

[0066] Step 302: Based on the first projection position information and the second projection position information, measure the first relative distance from the center of the first projection image to the center of the optical axis of the auxiliary positioning device.

[0067] The auxiliary positioning device can be configured to emit line laser or structured light directly onto the projection plane. Therefore, the center of the second projected image is the center of the optical axis of the auxiliary positioning device on the projection plane. Thus, the relative distance between the center of the first projected image and the center of the second projected image in the vertical direction is the first relative distance from the center of the first projected image to the center of the optical axis of the auxiliary positioning device.

[0068] As an example, step 302 includes: locating the center position of the first projected image based on the first projection position information to obtain first center position information; locating the center position of the second projected image based on the second projection position information to obtain second center position information; and measuring the relative distance in the vertical direction between the center of the first projected image and the center of the second projected image based on the first center position information and the second center position information to obtain a first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device.

[0069] In one embodiment, measuring the first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device, based on the first projection position information and the second projection position information, includes:

[0070] Based on the first projection position information, the center position of the first projection image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0071] The first projection position information can be the coordinates of multiple key points in the first projection image, the second projection position information can be the coordinates of multiple key points in the second projection image, and the first center position information can be the coordinates of the first center position.

[0072] Specifically, based on the coordinates of multiple key points of the first projected image, the center position of the first projected image is located, and the first center position coordinates are obtained; based on the coordinates of multiple key points of the second projected image, the position of the optical axis center of the auxiliary positioning device in the vertical direction is located, and the vertical position coordinates of the optical axis center of the auxiliary positioning device in the vertical direction are obtained; based on the first center position coordinates and the vertical position coordinates, the first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device is calculated.

[0073] Step 304: Based on the first relative distance and the relative installation dimensions, measure the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine, wherein the relative installation dimensions are used to characterize the relative distance between the center of the optical axis of the optical engine and the center of the optical axis of the auxiliary positioning device.

[0074] Among them, the optical axis center of the optical engine can be the regional position center of the intersection area between the optical axis of the optical engine and the projection plane, and the optical axis center of the auxiliary positioning device can be the regional position center of the intersection area between the optical axis of the auxiliary positioning device and the projection plane; the relative installation dimension can be used to characterize the relative distance in the vertical direction between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device on the projection plane, that is, the relative distance in the vertical direction between the optical axis of the optical engine and the optical axis of the auxiliary positioning device.

[0075] As an example, step 304 includes: determining the relative positional relationship between the optical axis of the optical engine and the optical axis of the auxiliary positioning device in the vertical direction; and calculating the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine based on the relative positional relationship, the first relative distance, and the relative installation dimensions.

[0076] As an example, based on the relative positional relationship, the first relative distance, and the relative mounting dimensions, the second relative distance from the center of the first projected image to the optical axis center of the optical engine is calculated, including:

[0077] If the optical axis of the optical engine and the optical axis of the auxiliary positioning device are on the same horizontal plane, the first relative distance is taken as the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine. If the optical axis of the optical engine is above the optical axis of the auxiliary positioning device, the difference between the first relative distance and the relative installation size is calculated to obtain the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine. If the optical axis of the optical engine is below the optical axis of the auxiliary positioning device, the sum of the first relative distance and the relative installation size is calculated to obtain the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine.

[0078] Step 306: Determine the off-axis ratio of the optical engine based on the second relative distance and the image height of the first projected image.

[0079] As an example, step 306 includes: dividing the second relative distance by half the height of the first projected image to obtain the off-axis ratio of the optical engine.

[0080] As an example, refer to Figure 5 In this embodiment, the camera screen is the camera's shooting plane, the DMD plane is the projection plane, ABCD is the first projected image with a resolution of 1920*1080, EF is the line laser projection, which is also the first projected image, abcd is the first image area, ef is the second image area, and O is the center of the first projected image. The formula for calculating the off-axis ratio of the optical engine in this embodiment is as follows:

[0081] offset = (OH + t0) / OG * 100%

[0082] Where offset is the off-axis ratio of the optical engine, OH is the first relative distance from the center of the first projected image to the center of the optical axis of the auxiliary positioning device. If the optical axis of the optical engine and the optical axis of the auxiliary positioning device are on the same horizontal plane, then t0 is 0. If the optical axis of the optical engine is above the optical axis of the auxiliary positioning device, then t0 is a negative value relative to the installation size. If the optical axis of the optical engine is below the optical axis of the auxiliary positioning device, then t0 is a positive value relative to the installation size. OG is half the height of the first projected image.

[0083] In this embodiment, based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimensions, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine. Since the relative installation dimensions are used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device, the second relative distance from the center of the first projected image to the optical axis center of the optical engine can be quantitatively measured using the relative installation dimensions. Therefore, based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine can be determined. Since the first projection position information, the second projection position information, and the relative installation dimensions are not measured with the optical axis as the reference, the measurement accuracy of the first projection position information, the second projection position information, and the relative installation dimensions can be guaranteed even if the optical axis is not visible. Therefore, the measurement accuracy of the off-axis ratio of the optical engine can be guaranteed.

[0084] In one embodiment, the second projected image includes a horizontal line laser projection; determining the first relative distance based on the first center position information and the second projection position information includes:

[0085] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0086] Among them, the second projection position information can be the coordinates of multiple key points of the line laser projection, the first center position information can be the coordinates of the first center position, and the vertical position information can be the coordinates of the vertical direction.

[0087] Specifically, the average value of the vertical coordinates of multiple key points in the line laser projection is calculated to obtain the vertical position coordinates of the optical axis center of the auxiliary positioning device in the vertical direction; the difference between the vertical position coordinates and the vertical coordinates of the first center position coordinates is calculated to obtain the first relative distance between the center of the first projected image and the line laser projection in the vertical direction.

[0088] In the above embodiments, by relying on the auxiliary positioning device to emit line lasers, a line laser projection can be formed on the projection plane. Based on the coordinates of multiple key points on the line laser projection, the position of the optical axis center of the auxiliary positioning device in the vertical direction can be accurately located, and the vertical position coordinates can be obtained. Thus, based on the vertical position coordinates and the vertical coordinates in the first center position coordinates, the first relative distance between the center of the first projected image and the line laser projection in the vertical direction can be quantitatively calculated, ensuring the accuracy of the measurement of the first relative distance, thereby laying the foundation for improving the measurement accuracy of the optical engine off-axis ratio.

[0089] In one embodiment, the second projected image includes structured light projection; determining the first relative distance based on the first center position information and the second projection position information includes:

[0090] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the fixed image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0091] Among them, the second projection position information can be the coordinates of multiple key points of the structured light projection, the first center position information can be the coordinates of the first center position, and the second center position information can be the coordinates of the second center position.

[0092] Specifically, based on the coordinates of multiple key points of the structured light projection, the projection center position of the structured light projection is located to obtain the second center position coordinates; the difference between the vertical coordinates in the first center position coordinates and the vertical coordinates in the second center position coordinates is calculated to obtain the first relative distance in the vertical direction between the center of the first projected image and the line laser projection.

[0093] In the above embodiments, structured light is emitted by an auxiliary positioning device, which can form a structured light projection on the projection plane. Based on the coordinates of multiple key points on the structured light projection, the projection center position of the structured light projection can be accurately located, and the second center position coordinates can be obtained. Thus, based on the vertical coordinates in the first center position coordinates and the vertical coordinates in the second center position coordinates, the first relative distance in the vertical direction between the center of the first projected image and the line laser projection can be quantitatively calculated, ensuring the accuracy of the measurement of the first relative distance, thereby laying the foundation for improving the measurement accuracy of the optical engine off-axis ratio.

[0094] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; based on the projective transformation relationship information between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image, including:

[0095] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; a projective transformation matrix is ​​determined based on the first projection position information and the first image position information; a projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0096] The first image position information can be multiple first image position coordinates, the second image position information can be multiple second image position coordinates, the first projection position information can be multiple first projection position coordinates, which are multiple key point coordinates of the first projection screen, and the second projection position information can be multiple second projection position coordinates, which are multiple key point coordinates of the second projection screen.

[0097] Specifically, by performing image recognition on the first image region, the position coordinates of each key point in the first image region are identified, resulting in multiple first image position coordinates; by performing image recognition on the second image region, the position coordinates of each key point in the second image region are identified, resulting in multiple second image position coordinates; based on the multiple first image position coordinates and the multiple first projection position coordinates, the projective transformation matrix between the camera shooting plane and the projection plane is calculated; based on the projective transformation matrix, the multiple second image position coordinates are projectively transformed to obtain multiple second projection position coordinates.

[0098] In the above embodiments, image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; a projective transformation matrix is ​​determined based on the first projection position information and the first image position information; and a projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information. In this way, the position coordinates of multiple key points in the second projection image can be quantitatively measured without relying on the optical axis as the measurement reference. Therefore, the measurement accuracy of the second projection position information can be guaranteed, laying the foundation for improving the measurement accuracy of the optical engine off-axis ratio.

[0099] When using an optical engine, it is inevitable that the optical engine will rotate in the vertical or horizontal direction. At this time, the projected image of the optical engine is no longer rectangular, but trapezoidal, which affects the projection effect. In order to improve the projection effect, it is necessary to correct the projected image of the optical engine, that is, to perform anti-trapezoidal correction.

[0100] Projection image correction relies on the off-axis ratio of the optical engine. Currently, if the theoretical off-axis ratio in the optical engine manual is used for projection image correction, there is a certain difference between the theoretical and actual off-axis ratios of each optical engine due to manufacturing reasons, which will affect the correction effect of the projection image. If the off-axis ratio of the optical engine is measured manually by measuring the distance from the bottom edge of the projection screen to the center of the optical axis, the measurement accuracy is not high because the optical axis of the optical engine is invisible, and the distance from the bottom edge of the projection screen to the center of the optical axis is measured with the optical axis of the optical engine as the measurement reference. Therefore, the measurement accuracy of the optical engine off-axis ratio is also not high, which will also affect the correction effect of the projection image.

[0101] In one embodiment, after measuring the off-axis ratio of the optical engine based on the relative mounting dimensions between the optical engine and the auxiliary positioning device, first projection position information, and second projection position information, the method further includes:

[0102] Obtain the resolution of the projected image and the throw ratio of the optical engine; based on the resolution, throw ratio, and off-axis ratio, correct the projected image of the optical engine.

[0103] The projection ratio of the optical engine is equal to the projection distance of the optical engine divided by the width of the projection screen of the optical engine.

[0104] Specifically, the resolution of the projected image and the throw ratio of the optical engine are obtained. Based on the resolution of the projected image, the height and width of the projected image are determined. Based on the height, width, throw ratio, and off-axis ratio of the projected image, the coordinates of the four vertices of the corrected matrix projected image are calculated. Based on these four vertex coordinates, the optical engine is used to correct the projected image.

[0105] As an example, the calculation process for the coordinates of the four vertices of the corrected matrix projection image, based on the projection image height, projection image width, throw ratio, and off-axis ratio, is as follows:

[0106] The coordinates of the top left vertex are (x1, y1, z1):

[0107] x1 = -length / 2

[0108] y1 = height * (offset / 2 + 0.5)

[0109] z1 = Q * length

[0110] The coordinates of the top right vertex are (x2, y2, z2):

[0111] x2 = length / 2

[0112] y2 = height * (offset / 2 + 0.5)

[0113] z2 = Q * length

[0114] The coordinates of the bottom left vertex are (x3, y3, z3):

[0115] x3 = -length / 2

[0116] y3 = height * (offset / 2 - 0.5)

[0117] z3 = Q * length

[0118] The coordinates of the bottom right vertex are (x4, y4, z4):

[0119] x4 = length / 2

[0120] y4 = height * (offset / 2 - 0.5)

[0121] z4 = Q * length

[0122] Where length is the width of the projected image, height is the height of the projected image, Q is the projection ratio, and offset is the off-axis ratio of the optical engine.

[0123] As an example, the resolution of the projected image is equal to the height of the projected image multiplied by the width of the projected image.

[0124] In the above embodiments, after measuring the off-axis ratio of the optical engine, the resolution of the projected image and the projection ratio of the optical engine are obtained. Based on the resolution, projection ratio, and off-axis ratio, the projected image of the optical engine can be corrected. Since the measurement of the off-axis ratio of the optical engine does not rely on the optical axis as a measurement reference for size, the measurement accuracy of the off-axis ratio of the optical engine is higher. Therefore, the accuracy of the projected image correction can be improved by using the more accurate off-axis ratio of the optical engine, resulting in a better effect of projected image correction.

[0125] In one embodiment, firstly, a projected image captured by a camera is acquired. This projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Next, first projection position information of the first projected image is acquired. Key point position recognition is performed on the projected image to obtain first image position information of the first image region and second image position information of the second image region. Based on the projective transformation matrix between the first projection position information and the first image position information, a projective transformation is performed on the second image position information to obtain the second projection position information of the second projected image on the projection plane. This allows the position of the second projected image on the projection plane to be located based on the projective transformation relationship between the shooting plane and the projection plane, thus obtaining the second projection position information.

[0126] After obtaining the second projection position information, the center position of the first projection image is located based on the first projection position information to obtain the first center position information; the center position of the second projection image is located based on the second projection position information to obtain the second center position information; based on the first and second center position information, the relative distance between the center of the first projection image and the center of the second projection image in the vertical direction is measured to obtain the first relative distance from the center of the first projection image to the optical axis center of the auxiliary positioning device. This allows for the measurement of the first relative distance from the center of the first projection image to the optical axis center of the auxiliary positioning device without relying on the optical axis as a measurement reference, ensuring the measurement accuracy of the first relative distance.

[0127] After measuring the first relative distance, the relative vertical positions of the optical axis of the optical engine and the optical axis of the auxiliary positioning device are determined. If the optical axis of the optical engine and the optical axis of the auxiliary positioning device are on the same horizontal plane, the first relative distance is taken as the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine. If the optical axis of the optical engine is above the optical axis of the auxiliary positioning device, the difference between the first relative distance and the relative installation dimension is calculated to obtain the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine. If the optical axis of the optical engine is below the optical axis of the auxiliary positioning device, the sum of the first relative distance and the relative installation dimension is calculated to obtain the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine. In this way, the second relative distance from the center of the first projected image to the center of the optical axis of the optical engine can be quantitatively measured by means of the relative installation dimension. This measurement process does not rely on the optical axis as a measurement reference, thus ensuring the measurement accuracy of the second relative distance.

[0128] After measuring the second relative distance, the second relative distance is divided by half the height of the first projected image to obtain the off-axis ratio of the optical engine. Since the first relative distance, the second relative distance, and the height of the first projected image are not dependent on the optical axis as the measurement reference, the off-axis ratio of the optical axis can be quantitatively measured without relying on the optical axis as the dimensional measurement reference. This ensures the measurement accuracy of the optical axis off-axis ratio, and the projection image correction can be performed based on the more accurate optical engine off-axis ratio, thereby improving the accuracy of the projection image correction and making the projection image correction effect better.

[0129] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0130] Based on the same inventive concept, this application also provides an optomechanical off-axis ratio measuring device for implementing the optomechanical off-axis ratio measuring method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations of one or more optomechanical off-axis ratio measuring device embodiments provided below can be found in the limitations of the optomechanical off-axis ratio measuring method described above, and will not be repeated here.

[0131] In one embodiment, such as Figure 6 As shown, an optomechanical off-axis ratio measuring device is provided, comprising: an image acquisition module, a projective transformation module, and a measurement module, wherein:

[0132] The image acquisition module is used to acquire the projected image captured by the camera. The projected image includes a first image area corresponding to a first projected image and a second image area corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane.

[0133] The projection transformation module is used to perform a projection transformation on the second image position information of the second image region based on the projection transformation relationship information between the first projection position information of the first projection image and the first image position information of the first image region, so as to obtain the second projection position information of the second projection image.

[0134] The measurement module is used to measure the off-axis ratio of the optical engine based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information.

[0135] In one embodiment, the measurement module is further configured to:

[0136] Based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimension, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimension is used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine is determined.

[0137] In one embodiment, the measurement module is further configured to:

[0138] Based on the first projection position information, the center position of the first projected image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0139] In one embodiment, the second projected image includes a horizontal line laser projection; the measurement module is further configured to:

[0140] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0141] In one embodiment, the second projected image includes structured light projection; the measurement module is further configured to:

[0142] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0143] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; the projective transformation module is further configured to:

[0144] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; the projective transformation matrix is ​​determined based on the first projection position information and the first image position information; the projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0145] In one embodiment, the optomechanical off-axis ratio measuring device further includes:

[0146] The projection image correction module is used to obtain the resolution of the projection image and the projection ratio of the optical engine; and to perform projection image correction on the optical engine based on the resolution, the projection ratio and the off-axis ratio.

[0147] Each module in the aforementioned optical engine off-axis ratio measuring device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the projection device in hardware form or independent of it, or stored in the memory of the projection device in software form, so that the processor can call and execute the corresponding operations of each module.

[0148] In one embodiment, a projection device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 7 As shown, the projection device includes a processor, memory, communication interface, optical engine, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements an optical engine off-axis ratio measurement method.

[0149] In one embodiment, the projection device may further include an auxiliary positioning device for generating a second projected image on the projection plane.

[0150] Those skilled in the art will understand that Figure 7The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the projection device to which the present application is applied. A specific projection device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0151] In one embodiment, a projection device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0152] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0153] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0154] Based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimension, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimension is used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine is determined.

[0155] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0156] Based on the first projection position information, the center position of the first projected image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0157] In one embodiment, the second projected image includes a horizontal line laser projection; the processor, when executing the computer program, also performs the following steps:

[0158] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0159] In one embodiment, the second projected image includes structured light projection; the processor, when executing the computer program, further implements the following steps:

[0160] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0161] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; the processor, when executing the computer program, further implements the following steps:

[0162] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; the projective transformation matrix is ​​determined based on the first projection position information and the first image position information; the projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0163] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0164] The resolution of the projected image and the projection ratio of the optical engine are obtained; the projected image is corrected based on the resolution, the projection ratio, and the off-axis ratio of the optical engine.

[0165] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0166] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0167] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0168] Based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimension, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimension is used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine is determined.

[0169] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0170] Based on the first projection position information, the center position of the first projected image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0171] In one embodiment, the second projected image includes a horizontal line laser projection; when the computer program is executed by the processor, it further performs the following steps:

[0172] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0173] In one embodiment, the second projected image includes structured light projection; when the computer program is executed by the processor, it further performs the following steps:

[0174] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0175] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; when the computer program is executed by a processor, it further implements the following steps:

[0176] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; the projective transformation matrix is ​​determined based on the first projection position information and the first image position information; the projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0177] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0178] The resolution of the projected image and the projection ratio of the optical engine are obtained; the projected image is corrected based on the resolution, the projection ratio, and the off-axis ratio of the optical engine.

[0179] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0180] The system acquires a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. Based on the projective transformation relationship between the first projection position information of the first projected image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projected image. Based on the relative installation dimensions between the optical engine and the auxiliary positioning device, the first projection position information, and the second projection position information, the off-axis ratio of the optical engine is measured.

[0181] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0182] Based on the first projection position information and the second projection position information, a first relative distance is measured from the center of the first projected image to the optical axis center of the auxiliary positioning device; based on the first relative distance and the relative installation dimension, a second relative distance is measured from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimension is used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; based on the second relative distance and the image height of the first projected image, the off-axis ratio of the optical engine is determined.

[0183] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0184] Based on the first projection position information, the center position of the first projected image is located to obtain the first center position information; based on the first center position information and the second projection position information, the first relative distance is determined.

[0185] In one embodiment, the second projected image includes a horizontal line laser projection; when the computer program is executed by the processor, it further performs the following steps:

[0186] Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; based on the vertical position information and the first center position information, the relative distance between the center of the first projection image and the line laser projection in the vertical direction is measured to obtain the first relative distance.

[0187] In one embodiment, the second projected image includes structured light projection; when the computer program is executed by the processor, it further performs the following steps:

[0188] Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is measured to obtain the first relative distance.

[0189] In one embodiment, the projective transformation relationship information includes a projective transformation matrix; when the computer program is executed by a processor, it further implements the following steps:

[0190] Image position recognition is performed on the first image region to obtain the first image position information; image position recognition is performed on the second image region to obtain the second image position information; the projective transformation matrix is ​​determined based on the first projection position information and the first image position information; the projective transformation is performed on the second image position information based on the projective transformation matrix to obtain the second projection position information.

[0191] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0192] The resolution of the projected image and the projection ratio of the optical engine are obtained; the projected image is corrected based on the resolution, the projection ratio, and the off-axis ratio of the optical engine.

[0193] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0194] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0195] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for measuring the off-axis ratio of an optomechanical system, characterized in that, The method includes: Acquire a projected image captured by a camera, wherein the projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image, the first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane; Based on the projective transformation relationship between the first projection position information of the first projection image and the first image position information of the first image region, a projective transformation is performed on the second image position information of the second image region to obtain the second projection position information of the second projection image. Based on the first projection position information and the second projection position information, a first relative distance is determined from the center of the first projected image to the optical axis center of the auxiliary positioning device; Based on the first relative distance and the relative installation dimensions, a second relative distance is determined from the center of the first projected image to the optical axis center of the optical engine, wherein the relative installation dimensions are used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; The off-axis ratio of the optical engine is determined based on the second relative distance and the image height of the first projected image.

2. The method according to claim 1, characterized in that, Determining the first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device based on the first projection position information and the second projection position information includes: Based on the first projection position information, the center position of the first projection image is located to obtain the first center position information; The first relative distance is determined based on the first center position information and the second projection position information.

3. The method according to claim 2, characterized in that, The second projected image includes a horizontal line laser projection; determining the first relative distance based on the first center position information and the second projection position information includes: Based on the second projection position information, the vertical position information of the line laser projection in the vertical direction is determined; Based on the vertical position information and the first center position information, the relative distance between the center of the first projected image and the line laser projection in the vertical direction is determined, and the first relative distance is obtained.

4. The method according to claim 2, characterized in that, The second projected image includes structured light projection; determining the first relative distance based on the first center position information and the second projection position information includes: Based on the second projection position information, the projection center position of the structured light projection is located to obtain the second center position information; Based on the first center position information and the second center position information, the relative distance between the image center and the projection center in the vertical direction is determined, and the first relative distance is obtained.

5. The method according to claim 1, characterized in that, The projective transformation relationship information includes a projective transformation matrix; the step of performing a projective transformation on the second image position information of the second image region based on the projective transformation relationship information between the first projection position information of the first projected image and the first image position information of the first image region to obtain the second projection position information of the second projected image includes: Image location recognition is performed on the first image region to obtain the first image location information; Image location recognition is performed on the second image region to obtain the second image location information; The projection transformation matrix is ​​determined based on the first projection position information and the first image position information; Based on the projective transformation matrix, the second image position information is projectively transformed to obtain the second projected position information.

6. The method according to any one of claims 1-5, characterized in that, After the step of determining the off-axis ratio of the optical engine based on the second relative distance and the image height of the first projected image, the method further includes: Obtain the resolution of the projected image and the throw ratio of the optical engine; The optical engine is used to correct the projected image based on the resolution, the projection ratio, and the off-axis ratio.

7. A device for measuring the off-axis ratio of an optomechanical system, characterized in that, The device includes: An image acquisition module is used to acquire a projected image captured by a camera. The projected image includes a first image region corresponding to a first projected image and a second image region corresponding to a second projected image. The first projected image is generated by an optical engine projecting onto a projection plane, and the second projected image is generated by an auxiliary positioning device projecting onto the projection plane. The projection transformation module is used to perform a projection transformation on the second image position information of the second image region based on the projection transformation relationship information between the first projection position information of the first projection image and the first image position information of the first image region, so as to obtain the second projection position information of the second projection image. The determining module is configured to: determine a first relative distance from the center of the first projected image to the optical axis center of the auxiliary positioning device based on the first projection position information and the second projection position information; determine a second relative distance from the center of the first projected image to the optical axis center of the optical engine based on the first relative distance and the relative installation dimensions, wherein the relative installation dimensions are used to characterize the relative distance between the optical axis center of the optical engine and the optical axis center of the auxiliary positioning device; and determine the off-axis ratio of the optical engine based on the second relative distance and the image height of the first projected image.

8. A projection device, comprising an optical engine, a memory, and a processor, wherein the memory stores a computer program, characterized in that, The optical engine is used to generate a first projected image on the projection plane, and the processor, when executing the computer program, implements the steps of the method according to any one of claims 1 to 6.

9. The projection device according to claim 8, characterized in that, The projection device also includes an auxiliary positioning device, which is used to generate a second projected image on the projection plane.

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