Automatic straightening method of projector

Abstract

The invention relates to an automatic correction method for a projector, and the method comprises the steps: transmitting a projection instruction to the projector, and controlling the projector to project a preset pattern; receiving a preset pattern shot by the camera in real time, and identifying feature points of the preset pattern; calculating a deviation angle of the preset pattern according to the feature points, and judging whether the deviation angle exceeds a preset angle threshold value or not; if yes, an angle adjusting instruction is sent to the holder, and the holder is controlled to adjust the projection angle of the projector. According to the technical scheme, through the automation technology, the problems that manual placement is poor in consistency, calibration time is long and the like can be effectively solved. The automatic calibration system can monitor the postures of the projectors in real time and automatically adjust the projection angle and position through an accurate sensor and an intelligent algorithm, it is ensured that calibration parameters of all the projectors are accurate and consistent, and the efficiency and the yield of a production line are greatly improved. Meanwhile, the automatic system can reduce errors caused by manual operation and improve the consistency and quality of products.

Description

Technical Field

[0001] The present application relates to the field of projectors, and in particular to an automatic alignment method for a projector. Background Art

[0002] In the production process of projectors, calibration is a key step to ensure the performance of the equipment, especially IMU (Inertial Measurement Unit) calibration and keystone correction calibration. IMU calibration is used to ensure the accuracy of the projector's attitude and direction data, while keystone correction calibration is to correct the deformation of the projected image at different projection angles and positions to ensure that the final displayed image is a square or rectangular. However, the current calibration process mainly relies on manual adjustment of the projector's position and angle to ensure that the projected image presents the correct geometric shape.

[0003] This manual alignment method has some significant drawbacks. First, differences in worker proficiency will directly affect the consistency of projector placement, resulting in deviations in the calibration results of each device. This not only makes the calibration effect unstable, but may also cause quality fluctuations in the finished product, reducing the yield rate. In addition, since manual alignment requires workers to repeatedly adjust the angle and position of the projector, the calibration time for each projector is long, usually taking several minutes to complete. This significantly reduces the work efficiency of the production line, limits the speed of the production line, and cannot meet the needs of large-scale production. Summary of the invention

[0004] The purpose of this application is to provide a method for automatically aligning a projector.

[0005] According to one aspect of the present application, there is provided a method for automatically aligning a projector, comprising:

[0006] Sending a projection instruction to the projector to control the projector to project a preset pattern;

[0007] Receiving the preset pattern photographed by a camera in real time, and identifying feature points of the preset pattern;

[0008] Calculating the offset angle of the preset pattern according to the feature points, and determining whether the offset angle exceeds a preset angle threshold;

[0009] If so, an angle adjustment instruction is sent to the pan-tilt head to control the pan-tilt head to adjust the projection angle of the projector.

[0010] Preferably, before the real-time receiving of the preset pattern photographed by the camera, the method further includes: correcting the positional relationship between the camera and the projection screen.

[0011] Preferably, the step of correcting the positional relationship between the camera and the projection screen comprises:

[0012] Project a first horizontal line and a first vertical line onto the projection screen through a first laser level, and project a second horizontal line and a second vertical line onto the projection screen through a second laser level. The first horizontal line, the second horizontal line, the first vertical line, and the second vertical line form a rectangular frame.

[0013] Receive in real time the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line captured by the camera, and adjust the pose of the camera so that the image captured by the camera is rectangular.

[0014] Preferably, the recognition of the straight lines includes: recognizing the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line through a straight line recognition algorithm, and the straight line recognition algorithm includes: Hough transform, LSD algorithm.

[0015] Preferably, the first laser level is placed on the left side of the camera and higher than the camera, and the second laser level is placed on the right side of the camera and lower than the camera.

[0016] Preferably, the feature points include: aruco code, geometric shape.

[0017] Preferably, the pan-tilt head includes: a yaw axis assembly for controlling the horizontal rotation of the projector; a roll axis assembly for controlling the roll rotation of the projector; a pitch axis assembly for controlling the up and down rotation of the projector; a processor electrically connected to the yaw axis assembly, the roll axis assembly, and the pitch axis assembly for receiving the adjustment instruction and controlling the rotation of each axis assembly according to the adjustment instruction.

[0018] Preferably, the pan-tilt head further includes an angle sensor for detecting and feedbacking the rotation angle of the pan-tilt head in real time.

[0019] Preferably, the processor includes: an abnormal state detection module for judging whether the pan-tilt head is in an abnormal state according to the rotation angle. If so, trigger a protection mode and control the pan-tilt head to rotate to a preset angle.

[0020] Preferably, the calculation of the offset angle of the preset pattern according to the feature points includes:

[0021] Detect and recognize the corner coordinates of the feature points of the preset pattern through OpenCV;

[0022] Calculate the offset angle through homography transformation and perspective transformation.

[0023] The present application has the following beneficial effects: Through automation technology, problems such as poor consistency in manual placement and long calibration time can be effectively solved. The automated calibration system can, through precise sensors and intelligent algorithms, monitor the posture of the projector in real time, automatically adjust the projection angle and position, ensure that the calibration parameters of each projector are accurately consistent, and greatly improve the efficiency and yield rate of the production line. At the same time, the automated system can also reduce human operation errors and improve product consistency and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a logical structure diagram of an automatic alignment method for a projector provided by an embodiment of the present application;

[0026] FIG. 2 is a projection diagram when the projector provided by an embodiment of the present application has a skew in the yaw axis direction;

[0027] FIG. 3 is a projection diagram when the projector provided by an embodiment of the present application has a skew in the pitch axis direction;

[0028] FIG. 4 is a projection diagram when the projector provided by an embodiment of the present application has a skew in the roll axis direction;

[0029] Figure 5 It is a flowchart of the projector screen alignment provided by an embodiment of the present application. SPECIFIC EMBODIMENTS

[0030] To facilitate the understanding of the present application, the following will describe the present application more comprehensively with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present application more thorough and comprehensive.

[0031] It should be noted that unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used in the description of the present application in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0032] Please refer toFigure 1 , an embodiment of the present application provides an automatic alignment method for a projector, including:

[0033] S1. Send a projection instruction to the projector to control the projector to project a preset pattern. In this step, it should be noted that a control instruction needs to be sent to the projector to ensure that it starts and projects the preset pattern. This pattern can be a specific shape or mark, such as a rectangular grid, a crosshair, or other easily recognizable patterns. This pattern usually contains some clear feature points or boundaries, such as aruco codes, geometric shapes, etc., for subsequent image recognition and calculation.

[0034] S2. Receive the preset pattern captured by the camera in real time and identify the feature points of the preset pattern. In this step, it should be noted that the camera captures the projection screen by photographing the preset pattern projected by the projector. Through image processing algorithms, the system can identify the feature points in the pattern, such as aruco codes, geometric shapes, etc., in the pattern. These feature points are the basis for subsequent offset angle calculation. To ensure the recognition accuracy, parameters such as the resolution, shooting angle, and focal length of the camera need to match the preset pattern.

[0035] In an alternative embodiment, the following algorithms can be used to identify the feature points: corner detection algorithm, SIFT (Scale-Invariant Feature Transform), or SURF (Speeded-Up Robust Features), ORB (Oriented FAST and Rotated BRIEF) algorithm, template matching, image perspective transformation (Homography) analysis algorithm, etc.

[0036] Implementing the technical solution of this embodiment can ensure that the system can flexibly adapt to different situations and improve the overall system robustness by adopting a variety of alternative algorithms. According to the requirements of specific application scenarios, the most suitable algorithm can be selected to balance the performance and computational resource requirements, providing higher fault tolerance for the system. If a certain algorithm cannot achieve the expected effect in some cases, it can be switched to other algorithms for supplementation.

[0037] S3. Calculate the offset angle of the preset pattern based on the feature points, and determine whether the offset angle exceeds a preset angle threshold. In this step, it should be noted that based on the identified feature points, the system can calculate the deviation between the current projection state and the expected ideal state of the pattern, and then obtain the offset angle. The offset angle generally refers to the rotation angle of the pattern relative to the ideal projection plane, and possible deviations include inclination, rotation, etc. This calculation usually uses a mathematical model, such as based on image transformation (such as affine transformation or perspective transformation) to deduce the actual deformation of the pattern. Then, the system will determine whether the offset angle exceeds the preset angle threshold. If it exceeds the threshold, adjustment is required. If it does not exceed, it means that the current projection position and angle already meet the standards and no adjustment is needed.

[0038] In an alternative embodiment, calculating the offset angle of the preset pattern based on the feature points includes:

[0039] Detect and identify the corner coordinates of the feature points of the preset pattern through OpenCV. In this step, it should be noted that OpenCV can detect the corner points in the preset pattern and extract the coordinate information of each corner point.

[0040] Calculate the offset angle through homography transformation and perspective transformation. In this step, it should be noted that using the image coordinates of the four vertices, determine the skew direction of the projector. The skew direction is divided into three axes: the yaw axis, the pitch axis, and the roll axis. The calculations for these three axes will be discussed one by one below:

[0041] (1) When the projector is skewed in the yaw axis direction, the preset pattern (a rectangle in this embodiment) appears as a trapezoid that is larger on the left and smaller on the right as shown in Figure (2a) or smaller on the left and larger on the right as shown in Figure (2b) in the camera image. Larger on the left and smaller on the right indicates that the projector is skewed to the left, and smaller on the left and larger on the right indicates that the projector is skewed to the right.

[0042] The vector calculation formulas for its upper and lower edges are as follows:

[0043] t = (x t , y t ) = (x B - x A , y B - y A )

[0044] b = (x b , y b ) = (x C - x D , y C - y D )

[0045] Where t is the upper edge vector, b is the lower edge vector, and x and y represent the horizontal and vertical coordinates; the problem of judging the skew direction of the yaw axis is converted into the problem of judging the opening direction of the included angle between vector t and vector b, and the opening direction can be obtained by calculating the cross product of the two vectors:

[0046] C y = b × t = (x b y t -x t y b )

[0047] Where C y is the cross product of vector b and vector t; by comparing the relationship between C y and the set threshold (-threshold, threshold), the skew direction is judged: if C y < -threshold, the projector is skewed to the right; if C y > threshold, the projector is skewed to the left; if -threshold ≤ C y ≤ threshold, the projector has no skew.

[0048] (2) When the projector is skewed in the pitch axis direction, the characteristic vertices are shown as a trapezoid with a larger upper part and a smaller lower part as shown in Figure (3a) or a smaller upper part and a larger lower part as shown in Figure (3b) in the camera image. A larger upper part and a smaller lower part indicate that the projector is skewed upward, and a smaller upper part and a larger lower part indicate that the projector is skewed downward.

[0049] The vector calculation formulas for its left and right edges are as follows:

[0050] l = (x1, y l ) = (x D -x A , y D -y A )

[0051] r = (x r , y r ) = (x C -x B , y C -y B )

[0052] Where l is the left edge vector, r is the right edge vector, and x and y represent the horizontal and vertical coordinates; the problem of judging the skew direction of the pitch axis is converted into the problem of judging the opening direction of the included angle between vector l and vector r, and the opening direction can be obtained by calculating the cross product of the two vectors:

[0053] C p = l × r = (x l y r -xl y r )

[0054] C p is the cross product of vector l and vector r; by comparing the relationship between C p and the set threshold (-threshold, threshold), the skew direction is judged: if C p <-threshold, the projector is skewed downward; if C p >threshold, the projector is skewed upward; if -threshold ≤ C p ≤threshold, the projector has no skew.

[0055] (3) When the projector is skewed in the roll axis direction, the characteristic vertices are shown as non-horizontal upper and lower edges and non-vertical left and right edges in the camera image. As shown in Figure (4a), it is deflected counterclockwise, and as shown in Figure (4b), it is deflected clockwise.

[0056] The corresponding vectors are calculated by the following formula:

[0057] t=(x t ,y t )=(x B -x A ,y B -y A )

[0058] h=(1,0)

[0059] where t is the upper edge vector, h is the horizontal vector, and x and y represent the horizontal and vertical coordinates; the problem of judging the skew direction of the roll axis is converted into the problem of judging the opening direction of the angle between vector t and the horizontal vector, and the opening direction can be obtained by calculating the cross product of the two vectors:

[0060] C r =t×h=-y t

[0061] where C r is the cross product of the horizontal vector and vector t; by comparing the relationship between C r and the set threshold (-threshold, threshold), the skew direction is judged: if C r <-threshold, the projector is deflected clockwise; if C r >threshold, the projector is deflected counterclockwise; if -threshold ≤ C r ≤threshold, the projector has no skew.

[0062] S4. If yes, send an angle adjustment instruction to the pan-tilt head to control the pan-tilt head to adjust the projection angle of the projector. In this step, it should be noted that if the offset angle exceeds the preset angle threshold, the system will send an adjustment instruction to the pan-tilt head to control the pan-tilt head to adjust the projection angle of the projector. The pan-tilt head can adjust the projection direction of the projector in real time according to the calculated offset angle. During the pan-tilt head adjustment process, the system may need to execute steps S3 and S4 multiple times until the projection pattern meets the requirements.

[0063] In actual applications, the three-axis deflection of the projector is mixed together, that is, the projector will have deflections on the yaw, pitch, and roll axes at the same time, so the projected image is not just a trapezoid with larger left and smaller right or larger top and smaller bottom, but an irregular quadrilateral. Figure 5 As shown, in a specific embodiment, the three-axis deflection mixed together can be calculated in sequence according to the three axes of yaw, pitch, and roll, so as to achieve the purpose of aligning the projection image. Controlling the pan-tilt head to adjust the projection angle of the projector includes:

[0064] Use the camera to capture the projected image.

[0065] Calculate C y , by comparing C y The relationship between the set threshold (-threshold, threshold) is used to determine the gimbal adjustment direction: if C y <-threshold, the projector tilts to the right, and the PTZ is controlled to adjust the preset angle to the left; if C y >threshold, the projector tilts to the left, and the PTZ is controlled to adjust the preset angle to the left; if -threshold≤C y ≤threshold, the projector has no skew.

[0066] Calculate C p , by comparing C p The relationship between the set threshold (-threshold, threshold) is used to determine the gimbal adjustment direction: if C p <-threshold, the projector tilts downward, and the PTZ is controlled to adjust the preset angle upward; if C p >threshold, the projector tilts upward and the PTZ is controlled to adjust the preset angle downward; if -threshold≤C p ≤threshold, the projector has no skew.

[0067] Calculate C r , by comparing C r The relationship between the set threshold (-threshold, threshold) is used to determine the gimbal adjustment direction: if Cr <-threshold, the projector tilts clockwise, and the control gimbal adjusts a preset angle counterclockwise; if C r >threshold, the projector tilts counterclockwise, and the control gimbal adjusts a preset angle clockwise; if -threshold ≤ C r ≤ threshold, the projector has no tilt and the alignment is completed.

[0068] In this embodiment, the smaller the preset rotation angle, the finer the adjustment during alignment, but the slower the alignment speed; the larger the preset angle, the faster the alignment speed, but the coarser the adjustment during alignment, and it may not converge at the alignment point. The threshold and rotation angle can be adjusted according to the actual effect. In practical applications, the three-axis tilt of the projector is mixed together, that is, the projector will simultaneously tilt in the yaw, pitch, and roll axes. Then, the projected image is not simply a trapezoid with a larger left side and a smaller right side or a larger upper side and a smaller lower side, but an irregular quadrilateral. Implementing the technical solution of this embodiment, the mixed three-axis tilt can be disassembled and calculated sequentially according to the yaw, pitch, and roll axes, so as to achieve the purpose of aligning the projection image.

[0069] Implementing the technical solution of this embodiment can effectively solve problems such as poor consistency in manual placement and long calibration time through automation technology. The automatic calibration system can use precise sensors and intelligent algorithms to monitor the posture of the projector in real time, automatically adjust the projection angle and position, ensure that the calibration parameters of each projector are accurate and consistent, and greatly improve the efficiency and yield of the production line. At the same time, the automatic system can also reduce the error of manual operation and improve the consistency and quality of products.

[0070] In a specific embodiment, the gimbal includes: a yaw axis assembly for controlling the horizontal rotation of the projector; a roll axis assembly for controlling the roll rotation of the projector; a pitch axis assembly for controlling the up and down rotation of the projector; and a processor electrically connected to the yaw axis assembly, the roll axis assembly, and the pitch axis assembly, for receiving adjustment instructions and controlling the rotation of each axis assembly according to the adjustment instructions.

[0071] Furthermore, the gimbal further includes an angle sensor for detecting and feedbacking the rotation angle of the gimbal in real time. In an alternative embodiment, a gyroscope and an accelerometer can also be combined to provide more accurate attitude information and improve the reliability of automatic correction.

[0072] Furthermore, the processor includes: an abnormal state detection module, which is used to determine whether the gimbal is in an abnormal state according to the rotation angle. If so, a protection mode is triggered to control the gimbal to rotate to a preset angle. In an optional embodiment, an angle threshold (such as ±10°) can be set. When the gimbal rotates beyond a safe range, the abnormal state detection module triggers a self-recovery mechanism to automatically restore the gimbal to a preset safe angle to avoid damaging the hardware or affecting the calibration.

[0073] By implementing the technical solution of this embodiment, the angle of the projector can be controlled by the yaw axis, roll axis and pitch axis of the gimbal to achieve automatic adjustment, avoid errors caused by manual adjustment, improve the alignment accuracy of the projection image, and thus optimize the effect of IMU calibration and trapezoidal correction. Automated gimbal adjustment is used to make each projector placed consistently, reduce errors caused by differences in worker proficiency, improve calibration consistency, and thus improve yield rate. The automated gimbal can complete precise adjustments in a short time, reduce adjustment time, and improve the work efficiency of the production line. The rotation state of the gimbal is monitored in real time by an angle sensor, and the rotation angle is fed back to the processor to ensure that the gimbal is adjusted as expected to avoid excessive or insufficient adjustment. The abnormal state detection module can identify abnormal states of the gimbal (such as instability, jamming, over-limit rotation, etc.), trigger the protection mode in time, avoid equipment damage or calibration failure, and improve system stability and reliability.

[0074] In a specific embodiment, before receiving the preset pattern photographed by the camera in real time, the method further includes: calibrating the positional relationship between the camera and the projection screen.

[0075] In this embodiment, calibrating the positional relationship between the camera and the projection screen includes:

[0076] Projecting a first horizontal line and a first vertical line onto the projection screen by a first laser level, projecting a second horizontal line and a second vertical line onto the projection screen by a second laser level, wherein the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line form a rectangular frame;

[0077] A first horizontal line, a second horizontal line, a first vertical line, and a second vertical line captured by a camera are received in real time, and the position and posture of the camera are adjusted so that the image captured by the camera is rectangular.

[0078] Identifying the straight line includes: identifying the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line through a straight line identification algorithm, and the straight line identification algorithm includes: Hough transform and LSD algorithm.

[0079] In an optional embodiment, the first laser level is placed to the left of the camera, above the camera, and the second laser level is placed to the right of the camera, below the camera.

[0080] Implementing the technical solution of this embodiment, by projecting a reference line with a laser level, it ensures that the camera can capture a standardized rectangular area, avoiding the influence of lens distortion and the skew of the projection screen, and improving the accuracy of subsequent pattern recognition. Two laser levels are used to project a rectangular frame, and the reference line is detected and recognized by the camera, and the pose (position and angle) of the camera is calculated and adjusted to ensure that the camera is facing the projection screen directly, rather than being tilted or offset, improving the consistency of shooting.

[0081] This specific embodiment also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, it causes the processor to execute the steps of the method as described above.

[0082] This specific embodiment also provides a computer-readable storage medium, storing a computer program, and when the computer program is executed by a processor, it causes the processor to execute the steps of the method as described above.

[0083] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in this application can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0084] The above embodiments only represent several embodiments of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application.

Claims

1. An automatic alignment method for a projector, characterized in that, Including: Sending a projection instruction to a projector to control the projector to project a preset pattern; Receiving in real time the preset pattern captured by a camera and identifying the feature points of the preset pattern; Calculating the offset angle of the preset pattern according to the feature points and determining whether the offset angle exceeds a preset angle threshold; If so, sending an angle adjustment instruction to a pan-tilt head to control the pan-tilt head to adjust the projection angle of the projector.

2. The automatic alignment method of the projector according to claim 1, wherein Before receiving in real time the preset pattern captured by the camera, it further includes: correcting the positional relationship between the camera and the projection screen.

3. The automatic alignment method of a projector according to claim 2, characterized in that: The correcting the positional relationship between the camera and the projection screen includes: Projecting a first horizontal line and a first vertical line onto the projection screen through a first laser level, and projecting a second horizontal line and a second vertical line onto the projection screen through a second laser level, and the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line form a rectangular frame; Receiving in real time the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line captured by the camera, and adjusting the pose of the camera so that the captured image of the camera is rectangular.

4. The automatic alignment method of the projector according to claim 3, characterized in that The identifying the straight lines includes: identifying the first horizontal line, the second horizontal line, the first vertical line, and the second vertical line through a straight line recognition algorithm, and the straight line recognition algorithm includes: Hough transform, LSD algorithm.

5. The automatic alignment method of the projector according to claim 3, wherein, The first laser level is placed on the left side of the camera and higher than the camera, and the second laser level is placed on the right side of the camera and lower than the camera.

6. The automatic alignment method of the projector according to claim 1, wherein, The feature points include: aruco code, geometric shape.

7. The automatic alignment method of the projector according to claim 1, wherein The pan-tilt head includes: a yaw axis component for controlling the horizontal rotation of the projector; a roll axis component for controlling the roll rotation of the projector; a pitch axis component for controlling the up-and-down rotation of the projector; a processor electrically connected to the yaw axis component, the roll axis component, and the pitch axis component for receiving the adjustment instruction and controlling the rotation of each axis component according to the adjustment instruction.

8. The method for automatically aligning a projector according to claim 7, characterized in that: The pan-tilt head further includes an angle sensor for detecting and feeding back in real time the rotation angle of the pan-tilt head.

9. The automatic alignment method of the projector according to claim 8, characterized in that, The processor includes: an abnormal state detection module for determining whether the pan-tilt head is in an abnormal state according to the rotation angle, and if so, triggering a protection mode to control the pan-tilt head to rotate to a preset angle.

10. The automatic alignment method of the projector according to claim 1, wherein The calculating the offset angle of the preset pattern according to the feature points includes: Detecting and identifying the corner coordinates of the feature points of the preset pattern through OpenCV; Calculating the offset angle through homography transformation and perspective transformation.

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