WO2022183721A1

WO2022183721A1 - Projection correction method and apparatus, and projection system

Info

Publication number: WO2022183721A1
Application number: PCT/CN2021/120673
Authority: WO
Inventors: 冉鹏; 王鑫
Original assignee: 成都极米科技股份有限公司
Priority date: 2021-03-05
Filing date: 2021-09-26
Publication date: 2022-09-09
Also published as: CN114791687B; CN114791687A

Abstract

The present application discloses a projection correction method and apparatus, and a projection system. The projection system at least comprises: a projector light engine supporting optical axis shifting and a rotary mechanism used for adjusting a projection direction of the projector light engine. The method comprises: obtaining projection information of a projector light engine; obtaining posture information of the projector light engine; determining, according to the projection information and the posture information, first angle information by which a rotary mechanism needs to rotate when a projection direction of the projector light engine is adjusted to directly face the plane where a target projection region is located, and rotating the rotary mechanism according to the first angle information; determining a first shift amount of optical axis shifting according to the first angle information, and performing optical axis shifting on the projector light engine according to the first shift amount. The present application solves the technical problem in the related art that loss of image quality and an unprojected edge effect are present during the correction of a projection picture.

Description

Projection correction method, device and projection system

technical field

The present application relates to the field of projection technology, and in particular, to a projection correction method, device, and projection system.

Background technique

In daily use, the image projected by the projector should face the projection screen or projection wall as much as possible to ensure that the picture has no vertical or horizontal angle, so as to ensure the projection effect. However, in actual use, it is often difficult to make the optical-mechanical projection screen face the projection surface in many scenarios. For example, in the scenarios of ceiling installation or bedroom use, basically the projection projection direction and the projection surface will have vertical or horizontal clips. horn. In this case, the projected image will present a non-rectangular trapezoid state. If you need to adjust the trapezoidal image to a standard rectangle, you need to use the projected keystone correction function.

In the related art, the keystone correction of projection usually has two ways: manual and automatic. Manual means that the user calls up the adjustment setting menu, and adjusts the shape of the picture by manually controlling the positions of several vertices of the projection picture; The module collects the projection surface information, and automatically corrects the picture into a rectangle by automatically compensating for the projection position. However, whether it is manual or automatic, the image is adjusted by digital adjustment, that is, the pixel position of the projected picture is changed by software algorithm. There are two drawbacks in this method: 1) The adjusted picture resolution and image quality The quality will be lost due to zooming; 2) After adjustment, the normal display content will become smaller, but the internal structure of the optical machine cannot be completely blocked, so the user can see obvious gray borders around the normal screen content, and the more the screen is adjusted. Smaller, the larger the gray border.

For the above problems, no effective solution has been proposed yet.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a projection correction method, device, and projection system, so as to at least solve the technical problems of image quality loss and gray border effects in the related art when correcting a projected image.

According to an aspect of the embodiments of the present application, a projection correction method is provided, the method is applied to a projection system, and the projection system at least includes: a projection light machine supporting an optical axis shift and a light projector for adjusting the light projection machine A rotating mechanism for a projection direction, the method includes: acquiring projection information of the light projector; acquiring attitude information of the light projector; determining the projection of the light projector according to the projection information and the attitude information When the direction is adjusted to face the projection surface, the rotation mechanism needs first angle information to rotate, and rotates the rotation mechanism according to the first angle information, wherein the projection surface is the plane where the target projection area is located ; Determine a first offset amount of the optical axis shift according to the first angle information, and perform an optical axis shift on the optical projector according to the first offset amount.

Optionally, the projection information of the light projector is acquired through an image acquisition module, and the projection information includes at least one of the following: projection image information, feature map information, and depth information of the projection surface.

Optionally, the attitude information of the light projector is acquired through an attitude sensor, and the attitude information includes at least attitude angle information of the light projector.

Optionally, determine the three-dimensional point cloud information and screen coordinate information of the projection surface according to the projection information; perform plane fitting according to the three-dimensional point cloud information and the screen coordinate information to obtain the plane equation of the projection surface; The plane equation determines the horizontal rotation angle of the optical projector, and the horizontal rotation angle is the rotation angle of the rotating mechanism in the horizontal direction when the projection direction of the optical projector is adjusted to face the projection surface. angle; determine the vertical pitch angle of the light projector according to the plane equation or the attitude angle information, and the vertical pitch angle is when the projection direction of the light projector is adjusted to face the projection surface, the The rotation angle of the rotation mechanism in the vertical direction; the tilt angle of the projector is determined according to the attitude angle information, and the tilt angle is the rotation of the rotation mechanism when the projector is adjusted to be parallel to the horizontal plane. The angle of ; the horizontal rotation angle, the vertical pitch angle and the tilt angle are used as the first angle information.

Optionally, the rotating mechanism is driven to rotate by a first motor, and rotating the rotating mechanism according to the first angle information includes: determining the number of rotation steps of the first motor and the rotation speed of the rotating mechanism. The first correspondence between the rotation angles; according to the first correspondence and the first angle information, determine the direction in which the first motor needs to rotate and the number of rotation steps in the corresponding direction; according to the rotation direction and the number of rotation steps to control the first motor to drive the rotation mechanism to rotate.

Optionally, determine a second correspondence between the rotation angle of the rotating mechanism and the offset of the optical axis; according to the second correspondence and the first angle information, determine the When the projected image is adjusted to the target projection area, a first offset of the optical axis is performed, wherein the first offset includes a first horizontal offset in the horizontal direction and a first offset in the vertical direction. vertical offset.

Optionally, the first horizontal offset is determined according to the second correspondence and the horizontal rotation angle; the first vertical offset is determined according to the second correspondence and the vertical pitch angle quantity.

Optionally, the texture information of the projection surface is acquired, and the obstacle information in the target projection area is determined according to the texture information; according to the obstacle information, it is determined that the projection image is to be optically moved when avoiding obstacles. The second offset of the axis.

Optionally, when it is determined according to the obstacle information that the projection image is to be avoided from an obstacle, second angle information that the rotating mechanism needs to rotate, and the second angle information includes that the rotating mechanism rotates in a horizontal direction. The horizontal offset angle and the vertical offset angle rotated in the vertical direction; the second horizontal offset is determined according to the second corresponding relationship and the horizontal offset angle; according to the second corresponding relationship and the The vertical offset angle, which determines the second vertical offset.

Optionally, performing an optical horizontal shift on the projector according to the first horizontal offset and the second horizontal offset; and according to the first vertical offset and the second vertical offset The optical vertical axis of the projector is shifted by the shift amount.

Optionally, acquiring the second projection information and second posture information of the light projector; determining and adjusting the projection direction of the light projector to face-to-face projection according to the second projection information and the second posture information When the surface is facing, the rotating mechanism needs third angle information of rotation, and rotates the rotating mechanism according to the third angle information.

Optionally, the optical projector has a digital correction function, after the optical projector is optically shifted according to the first offset, a correction instruction of the target object is received, and the projection image is adjusted according to the correction instruction. Correction is performed, wherein the correction instruction is used to instruct the projection image to be corrected again by the digital correction function.

According to another aspect of the embodiments of the present application, another projection correction method is provided, the method is applied to a projection system, the projection system at least includes: a projector light machine supporting an optical axis shift, and the method includes: acquiring projection information of the light projector; obtain the position information of the target projection area; determine the first offset of the optical axis shift in the light projector according to the projection information and the position information; The shift amount is used to optically shift the axis of the light projector, so as to adjust the projection image of the light projector to the target projection area.

Optionally, obtain obstacle information in the target projection area; determine a second offset of the optical axis shift in the projector according to the obstacle information; The optical projector performs optical axis shifting to avoid obstacles on the projected image.

According to another aspect of the embodiments of the present application, a projection correction device is also provided, including: a first acquisition module, configured to acquire projection information of a light projector and obstacle information in a target projection area; a second acquisition module, Used to obtain the attitude information of the light projector; the first determination module is used to determine that when the projection direction of the light projector is adjusted to face the projection surface according to the projection information and the attitude information, the rotating mechanism needs The first angle information of the rotation, wherein the projection plane is the plane where the target projection area is located; the rotation module is used to rotate the rotation mechanism according to the first angle information; the second determination module is used to determining a first offset of the optical axis shift according to the first angle information, and determining a second offset of the optical axis shift according to the obstacle information; an axis shift module for determining the first offset amount and The second offset optically shifts the optical axis of the projector.

According to another aspect of the embodiments of the present application, a projection system is also provided, including: a projector light machine supporting an optical tilt-shift function, for projecting a projection image to a target projection area, wherein the optical tilt-shift function is used for is used to adjust the position of the projection screen; the image acquisition module is used to obtain the projection information of the light projector and the texture information of the projection surface, wherein the texture information is used to determine the obstacles in the target projection area information; an attitude information acquisition module for acquiring the attitude information of the projector, the attitude information including at least the attitude angle information of the projector; a calculation processing module for according to the projection information and the attitude The information determines the first angle information that the rotation module needs to rotate when the projection direction of the projector is adjusted to face the projection surface; the rotation module is used to adjust the projection of the projector according to the first angle information. The projection direction is adjusted to face the projection surface.

According to another aspect of the embodiments of the present application, a non-volatile storage medium is further provided, the non-volatile storage medium includes a stored program, wherein the non-volatile storage medium is controlled when the program runs The device where the storage medium is located executes the above-mentioned projection correction method.

In the embodiment of the present application, by acquiring the projection information and attitude information of the light projector, the first angle information when the rotating mechanism is rotated is determined, and the rotating mechanism is rotated according to the first angle information, so that the The projection direction is adjusted to face the projection surface, and then, according to the first angle information, the first offset of the optical axis shift is calculated and the optical axis of the projector is optically shifted, so as to project the projection image to the target projection area; at the same time, obtain the target According to the obstacle information in the projection area, the second offset of the optical axis shift is determined according to the obstacle information, and the optical axis of the projector is optically shifted, so that the projection image avoids obstacles; By scaling the projection image, it can effectively solve the technical problems of image quality loss and gray border effect when correcting the projection image in the related art.

Description of drawings

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the attached image:

FIG. 1a is a schematic diagram of an optical horizontal axis shift of a light projector according to an embodiment of the present application;

Fig. 1b is a schematic diagram of an optical vertical axis shift of an optical projector according to an embodiment of the present application;

Fig. 2a is a schematic diagram of picture loss caused by a projection keystone correction according to the related art;

Figure 2b is a schematic diagram of a gray border generated by a projection keystone correction according to the related art;

3 is a schematic structural diagram of a projection system according to an embodiment of the present application;

4 is a schematic flowchart of a projection correction method according to an embodiment of the present application;

Fig. 5a is a schematic diagram of horizontal rotation projection of a light projector according to an embodiment of the present application;

Fig. 5b is a schematic diagram of vertical rotation projection of a light projector according to an embodiment of the present application;

5c is a schematic diagram of oblique projection of a light projector according to an embodiment of the present application;

6 is a schematic diagram of the relationship between the rotation angle of the projector and the screen offset according to an embodiment of the present application;

7 is a schematic diagram of a projection image avoiding obstacles according to an embodiment of the present application;

8 is a schematic flowchart of a projection correction process according to an embodiment of the present application;

9 is a schematic flowchart of another projection correction method according to an embodiment of the present application;

FIG. 10 is a schematic structural diagram of a projection correction device according to an embodiment of the present application.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only The embodiments are part of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of protection of the present application.

It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

In order to better understand the embodiments of the present application, some nouns or terms that appear in the process of describing the embodiments of the present application are translated and explained as follows:

Optical tilt-shift: Similar to the principle of camera tilt-shift, the optical projector also has an optical tilt-shift system. As long as the internal lens of the optical machine is shifted slightly, the projected optical image can be almost unchanged in shape. With a large displacement, the displacement change of the projected image caused by the displacement of the optical system of the lens is much larger than the displacement change of the projected image caused by the direct displacement of the projector to the same size. Usually, the optical axis shift of the projector includes a horizontal axis and a vertical axis. Figure 1a is a schematic diagram of the optical horizontal axis shift, wherein 11 represents the projector, 12 represents the projection surface, and 13 represents the projector on the projection surface. 14 is the projection image on the projection surface after the optical machine is horizontally shifted, which realizes the large displacement of the projection image in the horizontal direction through the optical-mechanical axis shift system; Figure 1b is a schematic diagram of the optical vertical axis shift , where 11 represents the optical projector, 12 represents the projection surface, 13 represents the original projection image of the optical projector on the projection surface, and 15 represents the projected image on the projection surface after the optical projector is vertically shifted, which is shifted by the optical projector. The axis system realizes a large displacement of the projection screen in the vertical direction. Digitally correcting the displacement of the image can be achieved by electronic zooming and zooming or controlling the pixel point displacement, but at the cost of losing brightness, resolution and image quality, and leaving gray borders when intercepting the undisplayed part, thus reducing the quality of the image. But the optical axis shift system can realize the physical displacement of the optical imaging picture without the position of the projector light machine through the precise movement of the complex optical lens group, so as to have no effect on the picture quality and brightness , which can be said to be a lossless image processing technology.

Example 1

In the related art, when performing keystone correction on the projected image, the image shape is generally adjusted by manually controlling the positions of several vertices of the projected image, or the projected image information is collected by an image acquisition module, and the projected image is automatically compensated for the projected image. The picture is corrected into a rectangle. These methods use digital adjustment to adjust the image, that is, to change the pixel position of the projected picture through a software algorithm, which has two drawbacks: 1) The adjusted picture resolution and picture quality will be affected by Taking Figure 2a as an example, 21 is the standard projection image, and its horizontal pixel is 1920; 22 is the projection image when keystone distortion occurs, which is corrected by scaling the bottom edge; 23 is the rectangular image obtained after correction , the horizontal pixel is less than 1920, which causes the loss of image quality; 2) After adjustment, the normal display content will become smaller, but because the internal structure of the optical machine cannot completely block light, there are obvious gray borders around the projection screen, as shown in the figure 2b, where 24 is the trapezoidal projection image before correction, 26 is the rectangular projection image after correction, and 25 is the generated gray border. It can be seen that when the corrected screen is smaller, the generated gray border is larger.

In order to solve the above problems, an embodiment of the present application provides a projection system, the projection system at least includes: a projection light machine supporting optical axis shifting and a rotation mechanism for adjusting the projection direction of the projection light machine, so as to realize the projection image. Optical lossless automatic keystone correction and adaptive correction for intelligent obstacle avoidance, so as to optimize the image quality loss and gray border problems under projection digital keystone correction and digital adaptive correction.

FIG. 3 is a schematic structural diagram of an optional projection system according to an embodiment of the present application. As shown in FIG. 3 , the system includes the following modules:

The projector 30 supporting the optical axis-shift function is used to project the projection image to the target projection area, wherein the projection image can be shifted in the horizontal direction and the vertical direction through the optical axis-shift function, so as to realize the position of the projection image. Adjustment; usually, there is an optical-mechanical axis-shift motor control module in the projector, and the program controls the direction and offset of its axis-shift.

The image acquisition module 32 is used to obtain the projection information of the light projector and the texture information of the projection surface, wherein the texture information is used to determine the obstacle information in the target projection area; optionally, the image acquisition module includes a camera module or other Depth information measurement modules, such as tof (time of flight) modules, etc.

The attitude information acquisition module 34 is used to obtain the attitude information of the projector, and the attitude information includes at least the attitude angle information of the projector (usually the attitude caused by the plane of the object on which the projector is placed or the hoisting projector is not horizontal). angle); optionally, the attitude information acquisition module includes an IMU (Inertial Measurement Unit, that is, an inertial measurement unit) sensor such as a gyroscope or a G-Sensor (gravity sensor).

The computing processing module 36 includes units with computing processing capabilities such as MCU/CPU/GPU, etc., and is used to determine, according to the projection information and the attitude information, when adjusting the projection direction of the light projector to face the projection surface, the rotation module needs to rotate the first element. angle information;

The rotation module 38 is connected to the light projector 30 and is used to adjust the projection direction of the light projector to face the projection surface according to the first angle information; it is usually a mechanical rotation module, including a machine capable of adjusting up, down, left, right and tilt in six directions. The structure and the drive motor module can drive the light projector to perform six-direction mechanical rotation through the program control motor to drive the rotation module.

Under the above operating environment, an embodiment of the present application provides a projection correction method. It should be noted that the steps shown in the flowchart of the accompanying drawings may be executed in a computer system such as a set of computer-executable instructions, and, Although a logical order is shown in the flowcharts, in some cases steps shown or described may be performed in an order different from that herein.

FIG. 4 is a schematic flowchart of a projection correction method according to an embodiment of the present application. As shown in FIG. 4 , the method includes the following steps:

Step S402, obtaining projection information of the light projector.

In some optional embodiments of the present application, the projection information of the light projector is acquired through the image acquisition module, and the projection information includes at least one of the following: projection image information, feature map information, and depth information of the projection surface, wherein the projection surface is the plane where the target projection area is located.

Specifically, the projection image can be roughly projected into the target projection area, and then the projector projector projects the original projection image, or projects the specific image information that the image sensor needs to recognize (if the depth information sensor is used to collect data, no projection is required). The projection image can also be displayed), at this time, if the projection direction of the projector is not directly facing the projection surface, the projection image may be a distorted trapezoid. Then, use RGB camera modules or modules with depth information collection capabilities, such as tof camera modules, multi-point tof modules or binocular cameras or structured light modules, etc., to collect the projected picture information or feature map information Or projection information such as projection surface depth information for 3D reconstruction or calculation of projection attitude angle.

In some optional embodiments of the present application, the texture information of the projection surface may also be acquired through the image acquisition module, and the obstacle information in the target projection area may be determined according to the texture information. For example, the texture information of the projection surface is captured by the camera to determine whether there are obstacles such as switches, sockets, murals, etc. in the target projection area. moving distance.

Step S404, acquiring attitude information of the projector.

In some optional embodiments of the present application, the attitude information of the light projector can be obtained by using an attitude sensor, such as a gyroscope or other gravity sensor, and the attitude information includes at least attitude angle information of the light projector. When the projector is placed on an inclined desktop, the attitude sensor can obtain the attitude angle of the projector, including its pitch angle and tilt angle in the vertical direction.

Step S406, according to the projection information and the attitude information, determine the first angle information that the rotating mechanism needs to rotate when the projection direction of the light projector is adjusted to face the projection surface, and rotate the rotating mechanism according to the first angle information, wherein the projection The face is the plane where the target projection area is located.

In some optional embodiments of the present application, the first angle information includes: a horizontal rotation angle, a vertical pitch angle, and a tilt angle. Specifically, the first angle information can be determined through the following process:

Step S4061, determine the three-dimensional point cloud information and picture coordinate information of the projection surface according to the obtained projection information such as the projection picture information or the projection surface depth information, and the picture coordinate information can be the spatial coordinates of the four vertices of the projection picture, which is used to calculate the projection. The plane equation of the face.

Step S4062, perform plane fitting according to the obtained three-dimensional point cloud information and screen coordinate information, obtain the plane equation Fn of the projection surface, and calculate the normal vector n of the projection surface.

Step S4063, according to the plane equation Fn and the normal vector n, determine the horizontal rotation angle Ang_H of the light projector. The schematic diagram is shown in Figure 5a, where 51 represents the projector, 52 represents the projection surface, 53 represents the trapezoidal projection screen of the projector on the projection surface, and 54 represents the angle Ang_H that rotates the projector in the horizontal direction. The resulting orthographic rectangular projection screen is obtained.

Step S4064, determine the vertical pitch angle Ang_V of the light projector according to the plane equation Fn and the normal vector n, and the vertical pitch angle Ang_V is the angle at which the rotating mechanism rotates in the vertical direction when the projection direction of the light projector is adjusted to face the projection surface , the schematic diagram is shown in Figure 5b, wherein 51 represents the projector, 52 represents the projection surface, 55 represents the trapezoidal projection screen of the projector on the projection surface, and 56 represents the projector after the projector is rotated in the vertical direction by the angle Ang_V The obtained orthographic rectangular projection picture; optionally, the vertical pitch angle Ang_V may also be determined according to the obtained attitude angle information of the projector.

Step S4065: Determine the inclination angle Ang_Z of the light projector according to the attitude angle information. The inclination angle Ang_Z is the angle at which the rotating mechanism rotates when the light projector is adjusted to be parallel to the horizontal plane. The schematic diagram is shown in Figure 5c, wherein 51 denotes Light projector, 52 represents the projection surface, 57 is the oblique projection image of the projector on the projection surface, 58 is the rectangular projection image obtained by rotating the projector by the angle Ang_Z to make it parallel to the horizontal plane.

After the first angle information is determined, the rotating mechanism may be rotated according to the first angle information. Usually, the rotating mechanism is driven to rotate by a first motor, and the first motor may be a DC motor or a stepping motor. In some optional embodiments of the present application, the first corresponding relationship between the number of rotation steps of the first motor and the rotation angle of the rotating mechanism may be determined first; then the first motor may be determined according to the first corresponding relationship and the first angle information The required rotation direction and the number of rotation steps in the corresponding direction; and then control the first motor to drive the rotation mechanism to rotate according to the rotation direction and the number of rotation steps.

Specifically, the first correspondence between the number of rotation steps of the first motor and the rotation angle of the rotating mechanism needs to be established by collecting data in advance. An optional implementation is as follows: Assume that the number of rotation steps Hx of the first motor in the horizontal direction The relationship with the actual rotation angle Hy of the rotating mechanism in the horizontal direction is linear, so Hy=a*Hx+b, where a and b are calculated by collecting the actual rotation effect of the motor and the rotating mechanism; of course, the actual The relationship between the rotation angle of and the number of rotation steps may also be a nonlinear relationship. In this case, Hy=f(Hx) can be fitted by collecting the measured data set in advance. Similarly, it is also possible to collect data to fit the relationship between the number of rotation steps Vx of the first motor in the vertical direction and the actual rotation angle Vy of the rotating mechanism in the vertical direction: Vy=c*Vx+d or Vy=f(Vx) The relationship between the number of rotation steps Zx of the first motor in the inclined direction and the actual rotation angle Zy of the rotating mechanism in the inclined direction is Zy=e*Zx+f or Zy=f(Zx).

When the rotating mechanism is rotated according to the first angle information, the first corresponding relationship determined above can be used to calculate that when the rotating mechanism rotates the angles Ang_H, Ang_V and Ang_Z in the horizontal, vertical and inclined directions, respectively, the first motor is in the horizontal direction. , the number of rotation steps in the vertical and oblique directions, and the program controls the first motor to drive the rotating mechanism to rotate, and the rotating mechanism drives the projector to rotate so that the projection direction of the projector is facing the projection surface.

It should be noted that, after the projection direction of the light projector is made to face the projection surface through the above process, the projection picture can be adjusted to a rectangle, but the projection picture at this time has deviate from the original target projection area, and it needs to be further adjusted by optical axis shifting. Adjust the position of the projected screen.

Step S408 , determining a first offset of the optical axis shift according to the first angle information, and performing an optical axis shift on the projector according to the first offset.

In order to adjust the projection image to the target projection area, it is necessary to determine the first offset of the optical axis shift. In some optional embodiments of the present application, the second correspondence between the rotation angle of the projector (ie the rotation angle of the rotation mechanism) and the offset of the optical axis may be determined first; according to the second correspondence and The first angle information determines the first offset of the optical axis shift when adjusting the projection image of the light projector to the target projection area. Since the first offset includes the first horizontal offset in the horizontal direction and the first vertical offset in the vertical direction, the first horizontal offset can be determined according to the second correspondence and the horizontal rotation angle; Two corresponding relationship and vertical pitch angle, determine the first vertical offset.

Specifically, as shown in FIG. 6 , 61 represents the projector, 62 represents the projection surface, 63 represents the trapezoidal projection image of the projector in the target projection area of the projection surface, and 64 represents the projector after being adjusted by the rotating mechanism. For the orthographic projection image on the projection surface, the distance L between the two is the final screen offset of the horizontal shift axis. Due to the horizontal rotation angle Ang_H of the projector and the final screen offset L of the horizontal shift axis It has a relationship similar to a right triangle, so the final screen offset L of the horizontal axis shift is a linear relationship proportional to the rotation angle Ang_H. On this basis, a Ang_H and the optical machine horizontal axis shift motor offset Len_H can be established This data table can be obtained by collecting the corresponding optical axis shift motor offset steps obtained from different angles, that is, Len_H=a*Ang_H+b, where a and b need to be combined with the design of the projector and the actual optics. The motion effect of the tilt-shift motor is calculated and fitted; optionally, considering that the actual image offset of the optical tilt-shift in the motor motion range may have errors rather than absolute linearity, it is possible to collect enough data to pass the actual non-linear motion. Linear relationship to fit, that is, Len_H=f(Ang_H). In the same way, the corresponding relationship between the offset Len_V of the vertical axis-shifting motor of the optical machine and the angle Ang_V of the vertical rotation of the projector light machine can also be obtained: Len_V=c*Ang_V+d or Len_V=f(Ang_V).

Considering that there may be obstacles such as switch sockets and murals in the target projection area, these obstacles need to be avoided during projection. Therefore, in some optional embodiments of the present application, the texture information of the projection surface can be obtained. The information determines the obstacle information in the target projection area; according to the obstacle information, when the projection image is determined to avoid the obstacle, a second offset of the optical axis shift is performed. Specifically, it is determined according to the acquired obstacle information that when the projection image is to avoid the obstacle, the second angle information that the rotating mechanism needs to rotate, the second angle information includes the horizontal offset angle rotated by the rotating mechanism in the horizontal direction and the horizontal offset angle of the rotating mechanism in the vertical direction. the vertical offset angle of the upward rotation; then, the second horizontal offset is determined according to the second corresponding relationship and the horizontal offset angle, the second vertical offset is determined according to the second corresponding relationship and the vertical offset angle, and the determined first Two horizontal offsets and a second vertical offset are used as second offsets.

For example, through the acquired texture information of the projection surface, it is judged whether there is an obstacle in the target projection area. If there is an obstacle, the direction in which the projection image needs to be displaced up and down or left and right and the coordinate value of the displacement are calculated. The depth information of the projection surface is the vertical distance. According to the difference between the target coordinate value and the original screen coordinate value, the angle Ang_H' or Ang_V' that needs to be fine-tuned up, down, left, and right for the projection position screen can be calculated by the principle of trigonometry, as shown in Figure 7, where , 71 is the projector light projector, 72 is the projection surface, 73 is the obstacle, 74 is the corrected rectangular projection picture, 75 is the projection picture after horizontal shifting by the first horizontal offset, which is partially covered by the obstacle Above, 76 is the projection picture obtained by fine-tuning the angle Ang_H' of the projector and avoiding the obstacle; then according to the second correspondence Len_H between the determined rotation angle of the projector and the offset of the optical axis shift =a*Ang_H+b or Len_H=f(Ang_H), the horizontal offset required to move the optical-mechanical horizontal shift axis to avoid obstacles can be calculated D_H=a*Ang_H'+b or D_H=f(Ang_H'); the same According to the principle, the vertical offset D_V=c*Ang_V'+d or D_V=f(Ang_V') that the opto-mechanical vertical axis shift axis needs to move to avoid obstacles can be obtained.

Finally, perform optical horizontal shifting of the optical projector according to the first horizontal offset Len_H and the second horizontal offset D_H; perform optical horizontal shifting on the optical projector according to the first vertical offset Len_H and the second vertical offset D_V Shift the axis vertically to project the projected image on the target projection area and avoid obstacles.

In actual implementation, due to the error when the motor rotates or shifts the axis, the shape of the obtained projection image may have some small shape distortion. At this time, the projection information collection and plane equation calculation steps can be repeated, and the calculation needs to satisfy the projection image. Fine-tuned rotation angles Ang_H_1, Ang_V_1, Ang_Z_1 for the rectangle. In some optional embodiments of the present application, the second projection information and the second attitude information of the light projector are acquired; and the projection direction of the light projector is adjusted to face the projection surface according to the second projection information and the second attitude information. When , the rotating mechanism needs the third angle information of rotation, and rotates the rotating mechanism according to the third angle information. At this point, the physical correction of the projected image is completed, and finally the projected image in the target projection area is a rectangle without image quality loss and gray borders caused by digital correction, and obstacles are avoided at the same time.

Usually, the projector has a digital correction function, which changes the pixel position of the projected picture through a software algorithm. There are two ways: manual and automatic. Manually, that is, the user calls up the adjustment setting menu, and manually controls the position of several vertices of the projected picture. , to adjust the shape of the picture; the automatic mode is to collect the projection surface information through the image acquisition module, and automatically correct the picture into a rectangle by automatically compensating for the projection position.

In some optional embodiments of the present application, after the optical projector is optically shifted according to the first offset, a correction instruction of the target object may be received, and the projection screen may be corrected according to the correction instruction, wherein the correction instruction uses Correct the projected image again by the digital correction function as instructed.

It can be understood that, the projector light machine can correct the projection picture according to the above-mentioned projection correction method, and can also correct the projection picture by using the digital correction function. For example, when the rotating mechanism fails to automatically correct the projected image, or the user is still dissatisfied with the corrected projected image, the projected image can be re-corrected with the digital correction function according to the user's instruction by accepting the user's instruction. Correction.

In an optional embodiment of the present application, the complete process of calibrating the projection picture is shown in FIG. 8 :

1) Collect the projection screen/projection surface depth information through the image acquisition module;

2) Calculate the three-dimensional point cloud information and screen coordinate information of the projection surface according to the collected image or depth information;

3) Carry out plane fitting according to the three-dimensional point cloud information and the screen coordinate information, and obtain the plane equation of the projection surface;

4) Calculate the horizontal rotation angle Ang_H of the light projector according to the plane equation;

5) Determine the vertical pitch angle Ang_V of the projector according to the plane equation or the IMU attitude sensor;

6) Determine the tilt angle Ang_Z of the projector according to the IMU attitude sensor;

7) According to the first correspondence between the number of rotation steps of the motor and the rotation angle, and the Ang_H, Ang_V, and Ang_Z determined above, determine the direction in which the motor needs to rotate and the number of rotation steps;

8) Control the motor to drive the rotating mechanism to rotate according to the determined rotation direction and the number of rotation steps;

9) according to the horizontal rotation angle Ang_H, calculate the first horizontal offset Len_H of the optical horizontal shift axis;

10) Control the optical machine according to Len_H to perform horizontal shift axis, so that the projection picture is projected on the target projection area;

11) Obtain the texture information of the projection surface through the camera, identify the obstacle and calculate the second horizontal offset D_H or the second vertical offset D_V that needs to be moved to avoid the obstacle when the projection screen is shifted by the light machine;

12) according to D_H or D_V control optical machine to carry out horizontal or vertical axis shift fine-tuning, so that the projection picture is projected on the target projection area and avoid obstacles;

13) Repeat the process of collecting projection information and calculating the plane equation, and calculate the rotation angles Ang_H_1, Ang_V_1, and Ang_Z_1 that need to be fine-tuned for the projection screen to be a rectangle;

14) According to the first correspondence and Ang_H_1, Ang_V_1, Ang_Z_1, determine the direction and the number of rotation steps that the motor needs to rotate;

15) Control the motor to drive the rotating mechanism to rotate according to the determined rotation direction and the number of rotation steps;

16) Complete the physical correction of the projected image, and finally the projected image in the target projection area is a rectangle, and there is no image quality loss and gray borders caused by digital correction, and obstacles are avoided at the same time.

Example 2

According to an embodiment of the present application, another projection correction method is also provided, which can also run in the projection system of Embodiment 1. It should be noted that the steps shown in the flowchart of the accompanying drawings can be performed in a computer system such as a set of computers. Executable instructions are executed in a computer system and, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in an order different from that herein.

FIG. 9 is a schematic flowchart of a projection correction method according to an embodiment of the present application. As shown in FIG. 9 , the method includes the following steps:

Step S902, obtaining projection information of the light projector.

Step S904, obtaining the position information of the target projection area.

Step S906, determining the first offset of the optical shift axis in the light projector according to the projection information and the position information.

In step S908, the optical axis of the optical projector is optically shifted according to the first offset, so as to adjust the projection image of the optical projector to the target projection area.

In some optional embodiments of the present application, the obstacle information in the target projection area can also be obtained; the second offset of the optical axis shift in the light projector is determined according to the obstacle information; the projection is calculated according to the second offset The opto-mechanical performs an optical tilt to move the projected image away from obstacles.

It should be noted that part of the process of the projection correction method in this embodiment of the present application is the same as that of the projection correction method in Embodiment 1. Since Embodiment 1 has been described in detail, some details not reflected in this embodiment may refer to Example 1.

In the embodiment of the present application, by acquiring the projection information of the projector and the position information of the target projection area, determining the first offset of the optical axis shift and performing the optical axis shift of the projector, the projection image can be projected to the target projection area; at the same time, obtain the obstacle information in the target projection area, determine the second offset of the optical axis shift according to the obstacle information, and perform the optical axis shift of the projection light machine, so that the projection image can avoid obstacles.

Example 3

According to an embodiment of the present application, a projection correction device for implementing the above-mentioned projection correction method is also provided. As shown in FIG. 10 , the device includes a first acquisition module 100, a second acquisition module 102, a first determination module 104, The rotation module 106, the second determination module 108 and the axis shift module 110, wherein:

The first obtaining module 100 is used for obtaining the projection information of the light projector and the obstacle information in the target projection area.

In some optional embodiments of the present application, the projection information of the light projector is acquired through the image acquisition module, and the projection information includes at least one of the following: projection image information, feature map information, and depth information of the projection surface, wherein the projection surface is the plane where the target projection area is located; the texture information of the projection surface is obtained through the image acquisition module, and the obstacle information in the target projection area is determined according to the texture information.

The second acquiring module 102 is configured to acquire attitude information of the projector.

In some optional embodiments of the present application, the attitude information of the light projector can be acquired through an attitude sensor, such as a gyroscope or other gravity sensor, where the attitude information at least includes the inclination angle between the light projector and the horizontal plane.

The first determination module 104 is used to determine the first angle information that the rotation mechanism needs to rotate when the projection direction of the projector is adjusted to face the projection surface according to the projection information and the attitude information, wherein the projection surface is the location where the target projection area is located. flat.

In some optional embodiments of the present application, the 3D point cloud information and picture coordinate information of the projection surface are determined according to the obtained projection information such as projection picture information or projection surface depth information; Perform plane fitting to obtain the plane equation of the projection surface; according to the plane equation, determine the horizontal rotation angle of the rotating mechanism in the horizontal direction when the projection direction of the light projector is adjusted to face the projection surface; according to the plane equation or the attitude of the light projector The information determines the vertical pitch angle of the rotating mechanism in the vertical direction when the projection direction of the projector is adjusted to face the projection surface; the tilt angle of the projector is determined according to the attitude information; the horizontal rotation angle, vertical pitch angle and tilt angle are determined. as the first angle information.

The rotation module 106 is configured to rotate the rotation mechanism according to the first angle information.

In some optional embodiments of the present application, since the rotation mechanism is driven and rotated by the first motor, the first correspondence between the number of rotation steps of the first motor and the rotation angle of the rotation mechanism may be determined first; A corresponding relationship and the first angle information determine the required rotation direction of the first motor and the number of rotation steps in the corresponding direction; and then control the first motor to drive the rotating mechanism to rotate according to the rotation direction and the number of rotation steps.

The second determining module 108 is configured to determine the first offset of the optical axis shift according to the first angle information, and determine the second offset of the optical axis shift according to the obstacle information.

In some optional embodiments of the present application, the second correspondence between the rotation angle of the projector and the offset of the optical axis shift may be determined first; according to the second correspondence and the first angle information, the projection When the projection image of the optical machine is adjusted to the target projection area, a first horizontal offset of the optical horizontal axis shift and a first vertical offset of the optical vertical axis are performed. Considering that there may be obstacles in the target projection area, you can determine the second angle information that the rotating mechanism needs to rotate when avoiding the obstacles based on the obtained obstacle information. The second angle information includes the rotating mechanism rotating in the horizontal direction. The horizontal offset angle and the vertical offset angle rotated in the vertical direction; then, the second horizontal offset is determined according to the second corresponding relationship and the horizontal offset angle, and the second horizontal offset is determined according to the second corresponding relationship and the vertical offset angle. For the vertical offset, the determined second horizontal offset and the second vertical offset are used as the second offset.

The axis-shifting module 110 is used to perform optical axis-shifting of the projector according to the first offset and the second offset.

In some optional embodiments of the present application, the optical horizontal axis shift is performed on the optical projector according to the first horizontal offset and the second horizontal offset; The optical projector performs an optical vertical axis shift, so that the projection image is projected on the target projection area and avoids obstacles.

It should be noted that each module in the projection correction device in this embodiment of the present application corresponds to the implementation steps of the projection correction method in Embodiment 1. Since Embodiment 1 has been described in detail, some of the modules in this embodiment For details not shown, reference may be made to Embodiment 1, which will not be repeated here.

Example 3

According to an embodiment of the present application, a non-volatile storage medium is also provided, the non-volatile storage medium includes a stored program, wherein when the program runs, the device where the non-volatile storage medium is located is controlled to perform the above-mentioned projection correction method.

Optionally, when the program is running, the device where the non-volatile storage medium is located is controlled to perform the following steps: obtaining the projection information of the light projector and the obstacle information in the target projection area; obtaining the attitude information of the light projector; according to the projection information and attitude information to determine the first angle information that the rotating mechanism needs to rotate when the projection direction of the projector is adjusted to face the projection surface, and rotate the rotating mechanism according to the first angle information, wherein the projection surface is where the target projection area is located the plane; determine the first offset of the optical axis shift according to the first angle information, determine the second offset of the optical axis shift according to the obstacle information, and determine the projection light according to the first offset and the second offset The machine performs optical tilt shifting.

Optionally, when the program is running, the device where the non-volatile storage medium is located is controlled to perform the following steps: obtaining the projection information of the light projector; obtaining the position information of the target projection area; The first offset amount of the corresponding optical axis shift in the target projection area; the optical axis shift is performed on the projector light machine according to the first offset amount.

The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

In the above-mentioned embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are only illustrative, for example, the division of units may be a logical function division, and there may be other division methods in actual implementation, for example, multiple units or components may be combined or integrated into Another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of units or modules, and may be in electrical or other forms.

Units illustrated as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , which includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes .

The above are only the preferred embodiments of the present application. It should be pointed out that for those skilled in the art, some improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as The protection scope of this application.

Claims

A projection correction method, characterized in that the method is applied to a projection system, the projection system at least comprises: a projection light machine supporting optical axis shifting and a rotation mechanism for adjusting the projection direction of the projection light machine, the The methods described include:

obtaining projection information of the projector;

obtaining the attitude information of the projector;

According to the projection information and the attitude information, when the projection direction of the projector is adjusted to face the projection surface, the rotation mechanism needs to rotate the first angle information, and according to the first angle information The rotating mechanism rotates, wherein the projection surface is the plane where the target projection area is located;

A first offset of the optical axis is determined according to the first angle information, and the optical projector is optically shifted according to the first offset.
The method according to claim 1, wherein obtaining the projection information of the light projector comprises:

The projection information of the light projector is acquired through the image acquisition module, and the projection information includes at least one of the following: projection image information, feature map information, and depth information of the projection surface.
The method according to claim 2, wherein acquiring the attitude information of the light projector comprises:

The attitude information of the light projector is acquired through an attitude sensor, and the attitude information includes at least attitude angle information of the light projector.
The method according to claim 3, wherein, when it is determined according to the projection information and the attitude information that the projection direction of the light projector is adjusted to face the projection surface, the rotation mechanism needs to rotate the first Angle information, including:

determining the three-dimensional point cloud information and picture coordinate information of the projection surface according to the projection information;

performing plane fitting according to the three-dimensional point cloud information and the picture coordinate information to obtain the plane equation of the projection plane;

The horizontal rotation angle of the projector is determined according to the plane equation, and the horizontal rotation angle is that when the projection direction of the projector is adjusted to face the projection surface, the rotating mechanism rotates in the horizontal direction Angle;

The vertical pitch angle of the projector is determined according to the plane equation or the attitude angle information, and the vertical pitch angle is the rotation angle when the projection direction of the projector is adjusted to face the projection surface. The angle by which the mechanism rotates in the vertical direction;

determining the tilt angle of the light projector according to the attitude angle information, where the tilt angle is the angle at which the rotating mechanism rotates when the light projector is adjusted to be parallel to the horizontal plane;

The horizontal rotation angle, the vertical pitch angle, and the tilt angle are used as the first angle information.
The method according to claim 1, wherein the rotating mechanism is driven to rotate by a first motor, and rotating the rotating mechanism according to the first angle information comprises:

determining a first correspondence between the number of rotation steps of the first motor and the rotation angle of the rotating mechanism;

Determine the direction in which the first motor needs to rotate and the number of rotation steps in the corresponding direction according to the first correspondence and the first angle information;

The first motor is controlled to drive the rotation mechanism to rotate according to the direction of rotation and the number of rotation steps.
The method according to claim 4, wherein determining the first offset of the optical axis shift according to the first angle information comprises:

determining the second correspondence between the rotation angle of the rotating mechanism and the offset of the optical axis;

According to the second correspondence and the first angle information, it is determined that when the projection image of the projector is adjusted to the target projection area, a first offset of the optical axis is performed, wherein the first offset is An offset includes a first horizontal offset in a horizontal direction and a first vertical offset in a vertical direction.
The method according to claim 6, wherein, according to the second correspondence and the first angle information, when it is determined to adjust the projection screen of the light projector to the target projection area, an optical shift is performed. The first offset of the axis, including:

determining the first horizontal offset according to the second correspondence and the horizontal rotation angle;

The first vertical offset is determined according to the second correspondence and the vertical pitch angle.
The method according to claim 6, wherein after determining the first offset of the optical axis shift according to the first angle information, the method further comprises:

acquiring texture information of the projection surface, and determining obstacle information in the target projection area according to the texture information;

A second offset of the optical axis shift is determined according to the obstacle information when the projection image is to avoid obstacles.
The method according to claim 8, wherein determining, according to the obstacle information, a second offset for performing an optical axis shift when the projection image avoids obstacles, comprising:

When it is determined according to the obstacle information that the projection image needs to be rotated to avoid obstacles, the second angle information of the rotation mechanism needs to be rotated, and the second angle information includes the horizontal offset of the rotation of the rotation mechanism in the horizontal direction the angle and the vertical offset angle of the rotation in the vertical direction;

determining a second horizontal offset according to the second correspondence and the horizontal offset angle;

A second vertical offset is determined according to the second correspondence and the vertical offset angle.
The method according to claim 9, wherein the optically shifting the optical axis of the projector according to the first offset comprises:

performing an optical horizontal shift on the optical projector according to the first horizontal offset and the second horizontal offset;

Perform an optical vertical shift of the optical projector according to the first vertical offset and the second vertical offset.
The method according to claim 1, characterized in that after optically shifting the optical axis of the projector according to the first offset, the method further comprises:

acquiring second projection information and second attitude information of the projector;

According to the second projection information and the second attitude information, when the projection direction of the projector is adjusted to face the projection surface, the third angle information that the rotation mechanism needs to rotate is determined, and according to the third The angle information rotates the rotating mechanism.
The method according to claim 1, wherein the optical projector has a digital correction function, and after optically shifting the optical axis of the optical projector according to the first offset, the method further comprises:

A correction instruction of the target object is received, and the projection image is corrected according to the correction instruction, wherein the correction instruction is used to instruct the projection image to be corrected again by the digital correction function.
A projection correction method, characterized in that, the method is applied to a projection system, the projection system at least includes: a projection light machine supporting an optical axis shift, and the method includes:

obtaining projection information of the projector;

Obtain the location information of the target projection area;

determining a first offset of the optical axis shift in the projector according to the projection information and the position information;

The optical axis of the light projector is optically shifted according to the first offset, so as to adjust the projection image of the light projector to the target projection area.
The method of claim 13, wherein the method further comprises:

obtain obstacle information in the target projection area;

determining a second offset of the optical shift axis in the projector according to the obstacle information;

The optical axis of the projector is optically shifted according to the second offset, so as to avoid obstacles on the projected image.
A projection correction device, comprising:

a first acquisition module, used for acquiring projection information of the projector;

a second acquisition module, configured to acquire the attitude information of the projector;

a first determining module, configured to determine, according to the projection information and the attitude information, the first angle information that the rotation mechanism needs to rotate when the projection direction of the light projector is adjusted to face the projection surface, wherein the projection The face is the plane where the target projection area is located;

a rotation module, configured to rotate the rotation mechanism according to the first angle information;

a second determining module, configured to determine the first offset of the optical axis shift according to the first angle information;

An axis-shifting module is used for optically shifting the optical axis of the projector according to the first offset.
A projection system, characterized in that, comprising:

A projector light machine supporting an optical tilt-shift function, used for projecting a projection picture to a target projection area, wherein the optical tilt-shift function is used to adjust the position of the projection picture;

an image acquisition module for acquiring projection information of the projector;

an attitude information acquisition module, configured to acquire attitude information of the projector, the attitude information including at least attitude angle information of the projector;

a calculation processing module, configured to determine the first angle information that the rotation module needs to rotate when the projection direction of the projector is adjusted to face the projection surface according to the projection information and the attitude information;

The rotation module is used for adjusting the projection direction of the light projector to face the projection surface according to the first angle information.
A non-volatile storage medium, characterized in that the non-volatile storage medium includes a stored program, wherein when the program is run, the device where the non-volatile storage medium is located is controlled to execute claims 1 to 1. The projection correction method described in any one of 14.