Projector keystone compensation parameter acquisition method, keystone compensation method, projector and storage medium

Abstract

The present application discloses a method for obtaining compensation parameters of a projector keystone correction, a keystone correction method, a projector and a storage medium. Before the projector is shipped, the optical engine rotation angle is obtained, the projector is placed in positions with horizontal angles equal to ±H degrees for testing, after the horizontal angle value is obtained by the angle obtaining module of the keystone correction model, the projection picture correction module of the ideal keystone correction model which corrects the optical engine rotation angle is called to perform keystone correction calculation, the four-point coordinates of the compensation corrected projection picture frame are obtained and projected, the aBeta value and offset value when the upper line of the projection picture is in a horizontal effect are taken, together with the optical engine rotation angle and the initial left and right inclination angles, as the keystone compensation parameters in the factory parameters of the projector. In use, the host obtains the V value and the current left and right inclination angles fed back by the gravity sensor, reads the keystone compensation parameters in the factory parameters stored, and obtains the corrected projection picture coordinates by the correction method of the present application and projects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of projector keystone correction, in particular to a projector keystone compensation parameter acquisition method, a keystone correction method, a projector and a storage medium. BACKGROUND

[0002] With the development of projection technology, keystone correction technology has become a standard function of the projector. There are many methods to achieve keystone correction, but the accuracy of various methods is different. But whether it is based on image algorithm keystone correction or distance sensor keystone correction, or manual adjustment keystone correction, it cannot avoid the calculation result deviation caused by the deviation of the projector structure and the deviation of the components in the engineering. Therefore, the parameters of each projector need to be re-accurate before leaving the factory.

[0003] Since the existing keystone correction model AutoKeystone is modeled under the ideal condition that the optical machine projection center axis is parallel to the projector base and the bottom edge of the projection picture is parallel to the base (offset value is 0), the keystone correction model generally includes an angle acquisition module and a projection picture correction module, and automatic keystone correction is performed by adjusting V and H values. V is the vertical angle between the optical machine projection center axis and the projector base, and H is the horizontal angle between the projection surface and the projection wall surface. But the ideal conditions cannot be guaranteed for mass-produced projector products. In actual production, there is a certain vertical angle between the optical machine projection center axis and the projector base, and the optical machine itself may have a certain rotation angle relative to the horizontal plane of the projector base. If the ideal keystone correction model AutoKeystone is used for automatic keystone correction, the calculation result will inevitably be inaccurate. In order to obtain more accurate keystone correction results, it is necessary to re-accurate the compensation parameters of each projector before leaving the factory, and it is necessary to propose a method for obtaining compensation parameters, so that the final keystone correction can be applied to omnidirectional keystone correction. SUMMARY

[0004] The purpose of the present application is to provide a projector keystone compensation parameter acquisition method, a keystone correction method, a projector and a storage medium, which uses a keystone correction model (hereinafter referred to as an ideal keystone correction model) including an angle acquisition module and a projection picture correction module modeled under ideal conditions, determines the keystone compensation parameters according to the different structural characteristics and component characteristics of the actual mass-produced projectors before leaving the factory, thereby compensating for the picture coordinate offset given by the ideal keystone correction model, and finally realizing omnidirectional automatic keystone correction. The keystone compensation parameters are applicable to camera calibration, tof calibration and manual calibration, and the angle acquisition module in the ideal keystone correction model can also be implemented in any of the three modes.

[0005] A projector keystone compensation parameter acquisition method according to the present application includes the following steps for acquiring keystone compensation parameters before the projector leaves the factory:

[0006] Step 11, set the test environment, so that the projection direction of the projector is perpendicular to the wall and is in a horizontal position;

[0007] Step 12, start the test, obtain and record the initial left-right tilt angle mThetaAngle of the light machine through the gravity sensor, and obtain the light machine rotation angle mAngle by measuring the projection picture of the projector. The calculation formula of the light machine rotation angle mAngle is as follows:

[0008]

[0009] Wherein, the light machine rotation angle mAngle is positive with the lower left corner point high and the lower right corner point low, the height difference of the left and right bottom edges of the projection picture is N, and the distance between the two measurement points of the left and right bottom edges of the projection picture is D;

[0010] Step 13, before the subsequent call of the ideal trapezoidal correction model for trapezoidal correction calculation, the projection picture of the light machine is first rotated by mAngle degrees to a horizontal state, that is, a step of setting the light machine rotation angle to 0 is added;

[0011] Step 14, assuming that the current offset value is 0, place the projector at a position where the projection surface and the projection wall form a horizontal angle equal to ±H degrees for testing. After measuring the horizontal angle beta value between the projection surface and the projection wall through the angle acquisition module of the ideal trapezoidal correction model, call the ideal trapezoidal correction model of step 13 for trapezoidal correction calculation, and obtain the four-point coordinates of the projection surface picture frame after compensation correction and projection;

[0012] Step 15, adjust the projection picture of step 14. When the upper edge of the projection picture is in a horizontal effect, assign the current horizontal angle beta value between the projection surface and the projection wall to aBeta: beta-->aBeta. When the bottom edge of the projection picture is in a horizontal effect, take the vertical direction offset of the coordinate of the point far away from the bottom edge of the projection picture in the horizontal effect as the offset value. Record the aBeta value and the offset value when the projector is located at a position where the projection surface and the projection wall form a horizontal angle equal to ±H degrees, respectively;

[0013] Step 16, take the light machine rotation angle mAngle, the initial left-right tilt angle mThetaAngle, the aBeta value and the offset value when the horizontal angle between the projection surface and the projection wall is ±H degrees as the trapezoidal correction compensation parameters of the projector, and store them in the factory parameters.

[0014] The step 14 is specifically:

[0015] The projector is placed at a position forming a horizontal angle with the projection surface and the projection wall surface equal to ±H degrees for testing, an ideal trapezoidal correction model angle acquisition module is used, the horizontal angle beta value of the projection surface and the projection wall surface is acquired through the ideal trapezoidal correction model angle acquisition module, the vertical elevation angle V value is acquired by using a gravity sensor, the beta value and the V value are substituted into the projection picture correction module of the ideal trapezoidal correction model of step 13 for trapezoidal correction calculation, and then the four-point coordinates of the projection surface picture frame are obtained, the current left-right tilt angle thetaAngle is acquired by using a gravity sensor, and then the above four-point coordinates are rotated according to the angle calculated by (mAngle-thetaAngle+mThetaAngle) respectively, and the four-point coordinates of the compensated and corrected projection surface picture frame are obtained and projected.

[0016] The trapezoidal correction method based on the trapezoidal correction compensation parameter acquired by the above-mentioned any one kind of projector trapezoidal correction compensation parameter acquisition method, comprising the following steps:

[0017] Step 21, in normal use, the user places the projector arbitrarily, the host acquires the V value and the current left-right tilt angle thetaAngle fed back by the gravity sensor, and reads the trapezoidal correction compensation parameters in the stored factory parameters: the optical machine rotation angle mAngle, the aBeta and offset values when the horizontal angle between the projection surface and the projection wall surface is ±H degrees;

[0018] The ideal trapezoidal correction model angle acquisition module of step 13 is used to acquire the current horizontal angle beta value between the projection surface and the projection wall surface;

[0019] Step 22, calculate and record the corrected horizontal angle beta_adjust between the projection surface and the projection wall surface, and the left-right correction amount needs to be recorded separately. If beta<0, the aBeta of-H degrees is used for calculation, otherwise the aBeta of +H degrees is used for calculation:

[0020] beta_adjust=beta*abs(aBeta) / H ;

[0021] Step 23, the corrected horizontal angle beta_adjust value between the projection surface and the projection wall surface and the V value are substituted into the trapezoidal correction module of the ideal trapezoidal correction model of step 13, and the four-point coordinates of the projection surface picture frame after trapezoidal correction are calculated;

[0022] Step 25, according to the offset value in the factory parameter, the current projection plane and the projection wall horizontal angle beta, the corrected four-point coordinate offset = offset*beta / H is obtained, when beta>0, according to the corrected four-point coordinate offset, the right lower point coordinate in the new four-point coordinate is adjusted, when beta<0, according to the corrected four-point coordinate offset, the left lower point coordinate in the new four-point coordinate is adjusted, to obtain the corrected four-point coordinate;

[0023] Step 25, the picture surrounded by the corrected four-point coordinate is rotated by the angle calculated by (mAngle-thetaAngle+mThetaAngle), to obtain the new four-point coordinate;

[0024] Step 26, according to the corrected four-point coordinate in step 25, the light machine projection picture is set and projected.

[0025] A projector, comprising a processor, a memory and a computer program stored in the memory and running on the processor, when the processor executes the computer program, the steps of the method are realized.

[0026] A computer readable storage medium, the computer readable storage medium stores a computer program, when the processor executes the computer program, the steps of the method are realized.

[0027] The present application obtains the light machine rotation angle before the projector is factory-produced, respectively places the projector in the position where the projection plane and the projection wall form a horizontal angle H equal to ±30 degrees to test, after the horizontal angle beta value of the projection plane and the projection wall is obtained by the angle acquisition module of the ideal trapezoidal correction model, the projection picture correction module of the ideal trapezoidal correction model which corrects the light machine rotation angle is called to carry out trapezoidal correction calculation, the four-point coordinate of the projection plane picture frame after compensation correction is obtained and projected, the aBeta value when the upper edge of the projection picture is in the horizontal effect is taken, the coordinate vertical direction offset of the point far from the bottom edge when the bottom edge of the projection picture is in the horizontal effect is taken as the offset value, together with the light machine rotation angle and the initial left and right inclination angle, as the trapezoidal correction compensation parameter in the factory parameter of the projector; in use, the user places the projector randomly, the host obtains the V value and the current left and right inclination angle thetaAngle fed back by the gravity sensor, and reads the trapezoidal correction compensation parameter in the factory parameter stored; the angle acquisition module of the ideal trapezoidal correction model which corrects the light machine rotation angle is used to obtain the current projection plane and the projection wall horizontal angle beta value, through the correction method of the present application, the corrected projection picture coordinate is calculated and projected.

[0028] The present application determines the trapezoidal correction compensation parameter according to the actual production of the projector's different structural characteristics and component characteristics before delivery, so as to compensate the picture coordinate offset given by the ideal trapezoidal correction model, and realize the all-directional automatic trapezoidal correction. The present application is applicable to batch production, and solves the problem of the increased error of trapezoidal correction caused by the deviation of the optical machine installation angle, position and the internal parameters of the optical machine. Since the error size is not fixed and the deviation direction is not fixed, it is impossible to use the fixed error correction parameter to batch correct, so each projector needs to be calibrated before delivery. If the present application is not used, the effect of trapezoidal correction will have a large error on different machines, and it is impossible to guarantee that each machine can be within the standard error. After using the present application, the trapezoidal correction rate of the delivery product reaches 100%. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The geometric diagram of the projection surface and the projection wall surface when V=0, H=30 degrees and the offset value is 0;

[0030] Figure 2 The geometric diagram of the projection wall surface when the optical machine rotation angle is 0, H is any angle and the offset value is 0;

[0031] Figure 3 The geometric diagram of the projection wall surface when H is not 0, the optical machine rotation angle is compensated and the offset value is not 0. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0033] Figure 1is the geometric diagram of the projection plane and the wall projection under ideal conditions (offset=0) when the vertical angle V between the optical machine projection center axis EO and the projector base is 0, and the horizontal angle H between the projection plane ABCD and the projection wall (A1B1C1D1) is 30 degrees, E is the projection origin of the optical machine, EO is the projection center axis of the optical machine, when offset=0, EO is perpendicular to the projection plane ABCD, EO intersects the bottom edge AB of the projection plane ABCD, and O is the midpoint of the bottom edge AB, the wall picture frame after the trapezoidal correction is A2B2C2D2, and the projection picture frame after the trapezoidal correction is A3B3C3D3, wherein A, A1, A2, A3 are coincident points, and D, D1, D2, D3 are coincident points (only when V=0). At this time, if the projection plane ABCD and the projection wall A1B1C1D1 form a horizontal angle H and a vertical angle V, the ideal trapezoidal correction model projection picture correction module can be used for automatic trapezoidal correction, and the algorithm is also a method commonly used in the market, which is manually adjusted V and H after trapezoidal correction.

[0034] As shown in Figure 2 , when the offset value is 0, EO intersects the bottom edge AB of the projection plane ABCD, that is, O falls on the bottom edge of the projection plane ABCD, the optical machine projects to the right, and the bottom edge of the projection wall remains horizontal. However, the ideal conditions cannot be guaranteed for mass-produced projectors. In actual production, the optical machine projection center axis EO is not parallel to the projector base, that is, the optical machine projection center axis EO does not intersect the bottom edge AB of the projection plane ABCD, and the projector center axis EO can pass through the inside or outside of the projection plane ABCD quadrilateral, in addition, the optical machine itself before mass production may have a certain rotation angle relative to the plane of the projector base, which means that the projection picture is rotated around the EO direction, which leads to the fact that the ideal trapezoidal correction model cannot be applied to each projector. As shown in Figure 3 , when the offset value is not 0, O does not fall on the bottom edge of the projection plane ABCD, O falls inside the projection plane ABCD (green frame), and when the optical machine projects to the right, it will cause the bottom edge A1B1 of the projection wall A1B1C1D1 to tilt to the right and down.

[0035] Embodiment one

[0036] Embodiment one of the application relates to a projector trapezoidal correction compensation parameter acquisition method, which acquires the following trapezoidal correction compensation parameter steps before the projector is shipped:

[0037] Step 11, set the test environment so that the projection direction of the projector is perpendicular to the wall and is in a horizontal position

[0038] Step 12, start the test, acquire and record the initial left-right tilt angle mThetaAngle of the light machine through the gravity sensor gsensor, acquire the light machine rotation angle mAngle by measuring the projection picture of the projector, and the calculation formula of the light machine rotation angle mAngle is as follows:

[0039]

[0040] Wherein, the light machine rotation angle mAngle is positive with the lower left corner point high and the lower right corner point low, the height difference of the left and right bottom edges of the projection picture is N, and the distance between the two measurement points of the left and right bottom edges of the projection picture is D;

[0041] Step 13, before the subsequent ideal trapezoidal correction model is called to perform trapezoidal correction calculation, the projection picture of the light machine is first rotated by mAngle angle to the horizontal state, that is, the step of setting the light machine rotation angle to 0 is added;

[0042] Step 14, assuming that the current offset value is 0, the projector is placed at a position forming a horizontal angle H equal to ±30 degrees with the projection surface and the projection wall surface respectively to test, after the horizontal angle beta value of the projection surface and the projection wall surface is measured by the angle acquisition module of the ideal trapezoidal correction model, the ideal trapezoidal correction model of step 13 is called to perform trapezoidal correction calculation, and the four-point coordinates of the projection surface picture frame after compensation and correction are obtained and projected, which is specifically:

[0043] The projector is placed at a position forming a horizontal angle H equal to ±30 degrees with the projection surface and the projection wall surface respectively to test, the horizontal angle beta value of the projection surface and the projection wall surface is acquired by using the angle acquisition module of the ideal trapezoidal correction model, the vertical elevation angle V value is acquired by using the gravity sensor gsensor, the beta value and the V value are substituted into the projection picture correction module of the ideal trapezoidal correction model of step 13 to perform trapezoidal correction calculation, and the four-point coordinates A3B3C3D3 of the projection surface picture frame are obtained, the current left-right tilt angle thetaAngle is acquired by using the gravity sensor gsensor, and the above four-point coordinates A3B3C3D3 are rotated by the angle calculated by (mAngle-thetaAngle+mThetaAngle) respectively, to obtain the four-point coordinates of the projection surface picture frame after compensation and correction and project;

[0044] Step 15, adjust the projection picture of step 14, when the upper edge of the projection picture is in horizontal effect, assign the current projection plane and the projection wall horizontal angle beta value to aBeta: beta-->aBeta; when the bottom edge of the projection picture is in horizontal effect, take the coordinate vertical direction offset of the bottom edge far point of the bottom edge of the projection picture in the horizontal effect as the offset value, that is, if H is positive, take the coordinate offset of the right point of the bottom edge as the offset value, if H is negative, take the coordinate offset of the left point of the bottom edge as the offset value, record the aBeta value and the offset value of the projector located in the position of the projection plane and the projection wall forming horizontal angle H equal to ±30 degrees respectively;

[0045] Step 16, take the optical machine rotation angle mAngle, the initial left and right inclination angle mThetaAngle, the aBeta value and the offset value of the projection plane and the projection wall forming horizontal angle H equal to ±30 degrees as the gradient calibration compensation parameters of the projector, and store them in the factory parameters.

[0046] The projector is preferably placed in the position of the projection plane and the projection wall forming horizontal angle H equal to ±30 degrees for testing, and is not limited to horizontal angle H equal to ±30 degrees. If H value is selected as other angles, subsequent calculation is modified accordingly.

[0047] The gradient calibration method based on the obtained gradient calibration compensation parameters comprises the following steps:

[0048] Step 21, in normal use, the user places the projector arbitrarily, the host obtains the V value and the current left and right inclination angle thetaAngle fed back by the gravity sensor gsensor, and reads the gradient calibration compensation parameters in the stored factory parameters: optical machine rotation angle mAngle, aBeta and offset value of the projection plane and the projection wall forming horizontal angle H equal to ±30 degrees;

[0049] The angle obtaining module of the ideal trapezoidal correction model of step 13 is used to obtain the horizontal angle beta between the current projection plane and the projection wall; if the image-based method is used, the feature picture in the ideal trapezoidal correction model is rotated and projected according to the rotation angle of the light machine, and then the horizontal angle beta between the current projection plane and the projection wall is obtained through trapezoidal correction calculation; if the tof method is used for trapezoidal correction, the distances d1 and d2 of two horizontal points from the wall are obtained by tof, and the horizontal angle beta between the current projection plane and the projection wall is calculated by substituting the ideal trapezoidal correction model of the tof method; if the method of manually adjusting the VH value is used, the H value set by the user is directly obtained as beta for subsequent calculation. Step 22, calculate and record the corrected horizontal angle beta_adjust between the projection plane and the projection wall, and the correction amount of the left and right needs to be recorded separately, if beta<0, use-30 degrees aBeta calculation, otherwise use+30 degrees aBeta calculation: beta_adjust=beta*abs(aBeta) / 30;

[0050] Step 23, substitute the corrected horizontal angle beta_adjust between the projection plane and the projection wall and the V value into the trapezoidal correction module of the ideal trapezoidal correction model of step 13, and calculate the four-point coordinates of the projection plane picture frame after trapezoidal correction;

[0051] Step 24, according to the offset value in the factory parameter, the horizontal angle beta between the current projection plane and the projection wall, the corrected four-point coordinate offset amount=offset*beta / H is obtained, when beta>0, the right lower point coordinate in the new four-point coordinate is adjusted according to the corrected four-point coordinate offset amount, when beta<0, the left lower point coordinate in the new four-point coordinate is adjusted according to the corrected four-point coordinate offset amount, and the corrected four-point coordinate is obtained;

[0052] Step 25, after the picture surrounded by the corrected four-point coordinates is rotated by the angle calculated by (mAngle-thetaAngle+mThetaAngle), the new four-point coordinates are obtained;

[0053] Step 26, the light machine projection picture is set according to the corrected four-point coordinates in step 25 and projected.

[0054] Embodiment two

[0055] The projector according to the embodiment two of the present application can include a processor (such as CPU), a memory, and a data acquisition device; the processor is connected to and controls the data acquisition device. The memory can store various instructions for completing various processing functions and realizing the processing steps described in the trapezoidal correction method based on the obtained trapezoidal correction compensation parameters in the aforementioned embodiment one.

[0056] Embodiment three

[0057] Embodiment three of the present application also provides a computer readable storage medium, which stores instructions, when the instructions are run on a computer, make the computer execute the processing steps described in the above embodiment one based on the obtained gradient compensation parameter.

[0058] Those skilled in the art should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present application can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, each example has been described in the above description in a general manner by function. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0059] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for obtaining projector ladder calibration compensation parameters, characterized in that... Before the projector leaves the factory, the following steps should be taken to obtain the ladder calibration compensation parameters: Step 11: Set up the test environment so that the projection direction of the projector is perpendicular to the wall and in a horizontal position; Step 12: Begin testing. Obtain and record the initial left and right tilt angle mThetaAngle of the optical engine using a gravity sensor. Obtain the rotation angle mAngle of the optical engine by measuring the projected image from the projector. The formula for calculating the rotation angle mAngle is as follows: Among them, the optical engine rotation angle mAngle is positive with the lower left corner point being higher and the lower right corner point being lower, the height difference between the left and right bottom edges of the projected image is N, and the distance between the two measurement points on the left and right bottom edges of the projected image is D; Step 13: Before performing keystone correction calculations using the ideal keystone correction model called later, rotate the projection screen of the optical engine by an angle mAngle to a horizontal state, that is, add the step of setting the optical engine rotation angle to 0. Step 14: Assuming the current offset value is 0, place the projector at a position where the horizontal angle between the projection surface and the projection wall is equal to ±H degrees for testing. After measuring the beta value of the horizontal angle between the projection surface and the projection wall through the angle acquisition module of the ideal trapezoidal correction model, call the ideal trapezoidal correction model in step 13 to perform trapezoidal correction calculation, obtain the coordinates of the four points of the frame of the compensated and corrected projection surface, and project them. Step 15: Adjust the projection screen from Step 14. When the top edge of the projection screen is horizontal, assign the beta value of the horizontal angle between the current projection surface and the projection wall to aBeta: beta --> aBeta. When the bottom edge of the projection screen is horizontal, take the vertical offset of the coordinates of the farthest point on the bottom edge as the offset value. That is, if H is positive, take the offset of the coordinates of the right side of the bottom edge as the offset value; if H is negative, take the offset of the coordinates of the left side of the bottom edge as the offset value. Record the aBeta value and offset value when the projector is located at a position where the horizontal angle between the projection surface and the projection wall is equal to ±H degrees. Step 16: The optical engine rotation angle mAngle, the initial left and right tilt angle mThetaAngle, the aBeta value and offset value when the horizontal angle between the projection surface and the projection wall is ±H degrees are used as the gradient compensation parameters of the projector and stored in the factory parameters.

2. The method for obtaining projector keyway compensation parameters according to claim 1, characterized in that... Step 14 specifically involves: The projector was placed at a position where the horizontal angle between the projection surface and the projection wall was ±H degrees for testing. The angle acquisition module of the ideal trapezoidal correction model was used to obtain the beta value of the horizontal angle between the projection surface and the projection wall. The vertical elevation angle V value was obtained using a gravity sensor. The beta value and V value were substituted into the projection screen correction module of the ideal trapezoidal correction model in step 13 for trapezoidal correction calculation to obtain the coordinates of four points of the projection screen frame. The current left and right tilt angle thetaAngle was obtained using a gravity sensor. The above four coordinates were then rotated according to the angle calculated by (mAngle-thetaAngle+mThetaAngle) to obtain the four coordinates of the compensated and corrected projection screen frame and projected.

3. A ladder calibration method based on the ladder calibration compensation parameters obtained by any of the projector ladder calibration compensation parameter acquisition methods according to claim 1 or 2, characterized in that... Includes the following steps: Step 21: During normal use, the user places the projector anywhere. The host obtains the V value and the current left and right tilt angle thetaAngle fed back by the gravity sensor, and reads the laddering compensation parameters in the stored factory parameters: the optical engine rotation angle mAngle, and the aBeta and offset values ​​when the projection surface and the projection wall form a horizontal angle of ±H degrees. Using the angle acquisition module of the ideal trapezoidal correction model in step 13, obtain the beta value of the horizontal angle between the current projection surface and the projection wall surface; Step 22: Calculate and record the corrected horizontal angle beta_adjust between the projection plane and the projection wall. The left and right corrections need to be recorded separately. If beta < 0, use aBeta of -H degrees for calculation; otherwise, use aBeta of +H degrees for calculation. beta_adjust=beta*abs(aBeta) / H; Step 23: Substitute the corrected horizontal angle beta_adjust value and V value between the projection surface and the projection wall into the trapezoidal correction module of the ideal trapezoidal correction model in Step 13 to calculate the coordinates of the four points of the projection surface frame after trapezoidal correction. Step 24: Based on the offset value in the factory parameters and the horizontal angle beta between the current projection surface and the projection wall, obtain the corrected four-point coordinate offset = offset * beta / H. When beta > 0, adjust the coordinates of the lower right point in the new four-point coordinate system according to the corrected four-point coordinate offset. When beta < 0, adjust the coordinates of the lower left point in the new four-point coordinate system according to the corrected four-point coordinate offset to obtain the corrected four-point coordinates. Step 25: Rotate the image enclosed by the corrected four-point coordinates by (mAngle-thetaAngle+mThetaAngle) and calculate the angle to obtain the new four-point coordinates; Step 26: Set the optical engine projection screen and project it according to the four-point coordinates corrected in Step 25.

4. A projector, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of the method as described in claim 3.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, it implements the steps of the method as described in claim 3.

Images