CN114827557A - Projection trapezoidal correction method and device and projection system - Google Patents
Projection trapezoidal correction method and device and projection system Download PDFInfo
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- CN114827557A CN114827557A CN202110247309.0A CN202110247309A CN114827557A CN 114827557 A CN114827557 A CN 114827557A CN 202110247309 A CN202110247309 A CN 202110247309A CN 114827557 A CN114827557 A CN 114827557A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3179—Video signal processing therefor
- H04N9/3185—Geometric adjustment, e.g. keystone or convergence
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
Abstract
The application discloses a projection trapezoidal correction method, a projection trapezoidal correction device and a projection system. Wherein the projection system comprises at least: the projector comprises a projector light machine and a rotating mechanism for adjusting the projection direction of the projector light machine. The method comprises the following steps: acquiring projection information of a projection optical machine; acquiring attitude information of a projection optical machine; determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located; and controlling the rotating mechanism to rotate according to the first angle information. The method and the device solve the technical problems of image quality loss and gray edge effect when the projection image is corrected in the related technology.
Description
Technical Field
The application relates to the technical field of projection, in particular to a projection trapezoidal correction method, a projection trapezoidal correction device and a projection system.
Background
In daily use, images projected by the projection light machine are required to be aligned to a projection screen or a projection wall as far as possible, so that the images are ensured not to have included angles in the vertical or horizontal direction, and the projection effect can be ensured. However, in practical use, it is often difficult to make the projection image of the optical machine directly face the projection plane in many scenes, for example, in a scene for hoisting or bedroom use, basically, the projection direction and the projection plane will have an included angle in the vertical direction or the horizontal direction. In this case, the projected picture will have a non-rectangular trapezoidal shape, and if the trapezoidal picture needs to be adjusted to a standard rectangular shape, the trapezoidal correction function for projection needs to be used.
In the related art, the projected trapezoidal correction usually has two modes, i.e., manual and automatic, in which a user calls up an adjustment setting menu and adjusts the shape of a projection picture by manually controlling the positions of several vertexes of the projection picture; the automatic mode is that the projection plane information is collected through an image collecting module, and the picture is automatically corrected into a rectangle through automatic compensation of the projection position. However, whether manual or automatic, the image is adjusted in a digital adjustment manner, that is, the positions of the projected picture pixels are changed by a software algorithm, and this method has two disadvantages: 1) the adjusted picture resolution and picture quality are lost due to scaling; 2) after the adjustment, the normal display content can become small, but the internal structure of the optical machine can not be completely shielded, so that a user can see that the periphery of the normal picture content has obvious gray edges, and the smaller the picture adjustment is, the larger the gray edges are.
In view of the above problems, no effective solution has been proposed.
Disclosure of Invention
The embodiment of the application provides a projection trapezoid correction method, a projection trapezoid correction device and a projection system, which are used for at least solving the technical problems of image quality loss and gray edge effect when a projection picture is corrected in the related technology.
According to an aspect of the embodiments of the present application, there is provided a projection keystone correction method, which is applied to a projection system, the projection system at least including: a light engine and a rotation mechanism for adjusting a projection direction of the light engine, the method comprising: acquiring projection information of the projection optical machine; acquiring attitude information of the projection optical machine; determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projector is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located; and controlling the rotating mechanism to rotate according to the first angle information.
Optionally, the projection information of the projection light engine is acquired through an image acquisition module, where the image acquisition module includes at least one of: the camera module and the depth information measuring module are arranged on the camera module; the projection information includes at least one of: projection picture information, feature map information and depth information of the projection plane.
Optionally, the attitude information of the projection light engine is acquired through an attitude sensor, and the attitude information at least includes attitude angle information of the projection light engine.
Optionally, determining 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 a plane equation of the projection plane and a normal vector of the plane equation; determining a horizontal rotation angle according to the plane equation and the normal vector, wherein the horizontal rotation angle is an angle of the rotation mechanism rotating in the horizontal direction when the projection direction of the projection light machine is adjusted to be opposite to the projection plane; determining a vertical pitch angle according to the plane equation and the normal vector, or determining the vertical pitch angle according to the attitude angle information, wherein the vertical pitch angle is an angle of the rotating mechanism rotating in the vertical direction when the projection direction of the projection light machine is adjusted to be opposite to the projection plane; determining an inclination angle of the projection optical machine according to the attitude angle information, wherein the inclination angle is an angle of rotation of the rotating mechanism when the projection optical machine is adjusted to be parallel to a horizontal plane; taking the horizontal rotation angle, the vertical pitch angle, and the tilt angle as the first angle information.
Optionally, the rotating mechanism is driven to rotate by a motor, and a first corresponding relation between the number of rotation steps of the motor and the rotation angle of the rotating mechanism is determined; determining the direction in which the motor needs to rotate and the number of rotating steps in the corresponding direction according to the first corresponding relation and the first angle information; and controlling the motor to drive the rotating mechanism to rotate according to the rotating direction and the rotating steps.
Optionally, the projection optical machine supports an optical shift function, determines an offset required to perform optical shift when the projection image of the projection optical machine is adjusted to the target projection area according to the first angle information, and performs optical shift on the projection optical machine according to the offset, where the offset includes a horizontal offset in a horizontal direction and a vertical offset in a vertical direction.
Optionally, the projection optical machine has a digital correction function, receives a correction instruction of a target object after controlling the rotation mechanism to rotate according to the first angle information, and corrects a projection picture according to the correction instruction, where the correction instruction is used to instruct to correct the projection picture again through the digital correction function.
According to another aspect of the embodiments of the present application, there is also provided a projection trapezoid correcting apparatus, including: the first acquisition module is used for acquiring projection information of the projection light machine; the second acquisition module is used for acquiring the attitude information of the projection optical machine; the first determining module is used for determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located; and the rotating module is used for controlling the rotating mechanism to rotate according to the first angle information.
According to another aspect of the embodiments of the present application, there is also provided a projection system, including: the projection light machine is used for projecting the projection picture to a target projection area; the image acquisition module is used for acquiring projection information of the projection light machine; the attitude information acquisition module is used for acquiring attitude information of the projection light machine, wherein the attitude information at least comprises attitude angle information of the projection light machine; the calculation processing module is used for determining first angle information which is required to rotate by the rotation module when the projection direction of the projection optical machine is adjusted to be opposite to the projection surface according to the projection information and the posture information; and the rotating module is used for adjusting the projection direction of the projection optical machine to be opposite to the projection surface according to the first angle information.
According to another aspect of the embodiments of the present application, there is also provided a non-volatile storage medium, where the non-volatile storage medium includes a stored program, and the program, when running, controls a device in which the non-volatile storage medium is located to execute the projection trapezoidal correction method.
In the embodiment of the application, the first angle information when the rotating mechanism rotates is determined by acquiring the projection information and the posture information of the projection optical machine, and the rotating mechanism is rotated according to the first angle information, so that the projection direction of the projection optical machine is adjusted to be opposite to the projection surface, and the original projection picture with trapezoidal distortion is corrected to be rectangular.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:
FIG. 1a is a diagram illustrating a loss of a picture caused by a projection keystone correction according to the related art;
FIG. 1b is a schematic illustration of a projection keystone correction resulting in gray edges according to the related art;
FIG. 2 is a schematic diagram of a projection system according to an embodiment of the present application;
FIG. 3 is a flowchart illustrating a method for projection keystone correction according to an embodiment of the present application;
FIG. 4a is a schematic diagram of a horizontal rotation projection of a light engine according to an embodiment of the present application;
FIG. 4b is a schematic diagram of a vertical rotation projection of a projection light engine according to an embodiment of the present application;
FIG. 4c is a schematic diagram of an oblique projection of a light engine according to an embodiment of the present application;
FIG. 5a is a schematic diagram of an optical horizontal shift of a projection optical engine according to an embodiment of the present application;
FIG. 5b is a schematic diagram of an optical vertical shift of a projection optical engine according to an embodiment of the present application;
FIG. 6 is a schematic diagram illustrating a relationship between a rotation angle of a projector and a frame offset according to an embodiment of the present disclosure;
FIG. 7 is a flow chart illustrating a projection correction process according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of a projection keystone correction apparatus according to an embodiment of the present application.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Example 1
In the related art, when performing keystone correction on a projection picture, generally, the picture shape is adjusted by manually controlling the positions of several vertexes of the projection picture, or an image acquisition module acquires projection picture information, and the projection picture is corrected into a rectangle by automatically compensating the projection position, which all adopt a digital adjustment mode to adjust the image, that is, the position of a projected picture pixel is changed by a software algorithm, which has two disadvantages: 1) the adjusted image resolution and image quality will be lost due to scaling, as shown in fig. 1a, wherein 11 is a standard projection image with horizontal pixels 1920; 12, correcting the bottom edge by scaling the projection picture when the trapezoidal distortion occurs; 13 is a rectangular picture obtained after correction, and the horizontal pixels of the rectangular picture are smaller than 1920, namely, the picture quality loss is caused; 2) after adjustment, the normal display content will be smaller, but because the internal structure of the optical engine cannot be completely shielded, there are obvious gray edges around the projection picture, as shown in fig. 1b, where 14 is the trapezoidal projection picture before correction, 16 is the rectangular projection picture after correction, and 15 is the generated gray edge, and it can be seen that the smaller the corrected picture, the larger the generated gray edge.
To solve the above problem, an embodiment of the present application provides a projection system, which at least includes: the projection optical machine and the rotating mechanism for adjusting the projection direction of the projection optical machine are used for realizing the optical lossless automatic trapezoidal correction of a projection picture, thereby optimizing the problems of image quality loss and gray edges under the projection digital trapezoidal correction.
FIG. 2 is a schematic diagram of an alternative projection system according to an embodiment of the present application, as shown in FIG. 2, which includes the following modules:
the optical projection engine 20 is configured to project the projection image to the target projection area, and optionally, the optical projection engine may support an optical shift function, and the optical shift function may perform displacement on the projection image in the horizontal direction and the vertical direction, so as to adjust the position of the projection image.
The image acquisition module 22 is configured to acquire projection information of the projection light engine, and optionally, the image acquisition module includes a camera module or other depth information measurement modules, such as a tof (time of flight) module.
A posture information collecting module 24, configured to obtain posture information of the projection optical engine, where the posture information at least includes posture angle information of the projection optical engine (usually, a posture angle caused by an object plane on which the projection optical engine is placed or a lifting of the projection optical engine being not horizontal); optionally, the attitude information collecting module includes an Inertial Measurement Unit (IMU) Sensor such as a gyroscope or a G-Sensor.
A calculation processing module 26, including units with calculation processing capability such as MCU/CPU/GPU, etc., for determining, according to the projection information and the posture information, a first angle information that the rotation module needs to rotate when the projection direction of the projection light engine is adjusted to be opposite to the projection surface;
a rotation module 28, connected to the optical projector 20, for adjusting the projection direction of the optical projector to be opposite to the projection plane according to the first angle information; the projector is generally a mechanical rotation module, and comprises a mechanical structure with six-direction adjustment capability of up-down, left-right and inclination and a driving motor module, and the motor driving rotation module can be controlled by a program to drive the projector to mechanically rotate in six directions.
In the operating environment described above, the embodiments of the present application provide a method for projective keystone correction, it should be noted that the steps illustrated in the flowchart of the drawings may be performed in a computer system such as a set of computer-executable instructions, and that while a logical order is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in an order different than here.
Fig. 3 is a schematic flowchart of a projection keystone correction method according to an embodiment of the present application, as shown in fig. 3, the method includes the following steps:
step S302, acquiring projection information of a projection light machine.
In some optional embodiments of the present application, the projection information of the projection light engine is acquired by an image acquisition module, where the image acquisition module includes at least one of: the camera module and the depth information measuring module are arranged on the camera module; the projection information includes at least one of: projection picture information, feature map information, depth information of the projection plane.
Specifically, the projection screen may be projected approximately in the target projection area, and at this time, the projection light engine projects an original projection screen, or projects specific image information that needs to be identified by the image sensor (if the depth information sensor is used to collect data, the projection screen does not need to be projected), and at this time, if the projection direction of the projection light engine is not directly opposite to the projection screen, the projection screen may be a trapezoid with distortion. Then, using an RGB camera module or a module with depth information acquisition capability, such as a tof camera module, a multi-point tof module, or a binocular camera or a structured light module, projection information used for three-dimensional reconstruction or calculation of a projection pose angle, such as projected picture information, feature map information, or projection plane depth information, is acquired.
Step S304, obtaining the attitude information of the projection light machine.
In some optional embodiments of the present application, the attitude information of the light engine can be obtained through an attitude sensor, such as a gyroscope or other gravity sensor, and the attitude information at least includes the attitude angle information of the light engine, for example, when the light engine is placed on an inclined desktop, the attitude angle of the light engine, including the pitch angle and the inclination angle thereof in the vertical direction, can be obtained through the attitude sensor.
Step S306, determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projector light machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where the projection picture is located.
In some optional embodiments of the present application, first, three-dimensional point cloud information and picture coordinate information of a projection plane are determined according to projection information, where the picture coordinate information may be spatial coordinates of four vertices of a projection picture; then, carrying out plane fitting according to the three-dimensional point cloud information and the picture coordinate information to obtain a plane equation of the projection plane; and then determining first angle information according to the plane equation and the attitude information, wherein the first angle information comprises a horizontal rotation angle, a vertical pitching angle and an inclination angle, and the specific process is as follows:
1) determining a plane equation Fn of the projection plane, and calculating a normal vector n of the projection plane;
2) determining a horizontal rotation angle Ang _ H of the projection light machine according to a plane equation Fn and a normal vector n, wherein the horizontal rotation angle Ang _ H is an angle of rotation of the rotating mechanism in a horizontal direction when the projection direction of the projection light machine is adjusted to be opposite to the projection plane, and a schematic diagram of the horizontal rotation angle Ang _ H is shown in fig. 4a, wherein 41 represents the projection light machine, 42 represents the projection plane, 43 represents a trapezoidal projection picture of the projection light machine on the projection plane, and 44 represents a forward projection rectangular projection picture obtained by rotating the projection light machine by the angle Ang _ H in the horizontal direction;
3) determining a vertical pitch angle Ang _ V of the projection light engine according to a plane equation Fn and a normal vector n, wherein the vertical pitch angle Ang _ V is an angle of the rotating mechanism rotating in the vertical direction when the projection direction of the projection light engine is adjusted to be opposite to the projection plane, and a schematic diagram of the vertical pitch angle Ang _ V is shown in fig. 4b, wherein 41 represents the projection light engine, 42 represents the projection plane, 45 represents a trapezoidal projection picture of the projection light engine on the projection plane, and 46 represents a forward projection rectangular projection picture obtained by rotating the projection light engine by the angle Ang _ V in the vertical direction; optionally, the vertical pitch angle Ang _ V may also be determined according to the acquired pose angle information of the projector;
4) an inclination angle Ang _ Z of the projection light engine is determined according to the attitude angle information, the inclination angle Ang _ Z is an angle that the rotation mechanism rotates when the projection light engine is adjusted to be parallel to the horizontal plane, and a schematic diagram thereof is shown in fig. 4c, wherein 41 represents the projection light engine, 42 represents the projection plane, 47 is an inclined projection picture of the projection light engine on the projection plane, and 48 is a forward projection rectangular projection picture obtained by rotating the projection light engine by the angle Ang _ Z to be parallel to the horizontal plane.
Step S308, controlling the rotation mechanism to rotate according to the first angle information.
After the first angle information is determined, the rotation mechanism may be rotated according to the first angle information. Generally, the rotating mechanism is driven by a motor, which may be a dc motor or a stepping motor. In some optional embodiments of the present application, a first corresponding relationship between the number of rotation steps of the motor and the rotation angle of the rotation mechanism may be determined; then, determining the direction in which the motor needs to rotate and the number of rotation steps in the corresponding direction according to the first corresponding relation and the first angle information; and then the motor is controlled to drive the rotating mechanism to rotate according to the rotating direction and the rotating steps.
Specifically, a first corresponding relationship between the number of rotation steps of the motor and the rotation angle of the rotating mechanism needs to be established by acquiring data in advance, and an optional implementation scheme is as follows: assuming that the relationship between the rotation step number Hx of the motor in the horizontal direction and the actual rotation angle Hy of the rotating mechanism in the horizontal direction is linear, there is 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 relationship between the actual rotation angle and the number of rotation steps may be a nonlinear relationship, and in this case, Hy ═ f (hx) may be fitted by collecting a measured data set in advance. Similarly, data can be collected to fit the relationship between the rotation step number Vx of the motor in the vertical direction and the actual rotation angle Vy of the rotating mechanism in the vertical direction into Vy (c) Vx + d or Vy (Vx); the relationship between the number of rotation steps Zx of the fitting motor in the pitch direction and the actual rotation angle Zy of the rotating mechanism in the pitch direction is Zy (e) Zx + f or Zy (f) (Zx).
When the rotating mechanism is rotated according to the first angle information, the rotating steps of the motor in the horizontal, vertical and inclined directions can be calculated through the determined first corresponding relation when the rotating mechanism is respectively rotated by the rotating angles Ang _ H, Ang _ V, Ang _ Z in the horizontal, vertical and inclined directions, and the rotating mechanism is controlled by a program to drive the motor to rotate, so that the rotating mechanism drives the projection optical machine to rotate, and the projection direction of the projection optical machine is opposite to the projection surface.
It should be noted that, after the projection direction of the projection optical engine is made to face the projection plane through the above process, the projection image may be adjusted to be rectangular, but the projection image at this time deviates from the original target projection area and may not meet the requirement of the user, so in some optional embodiments of the present application, a projection optical engine supporting the optical axis shifting function may be selected and used to perform the optical axis shifting after controlling the rotation mechanism to rotate according to the first angle information.
The principle of optical shift is similar to that of camera shift, so that the projected optical picture can be greatly shifted in the condition of almost unchanged shape by only slightly shifting the lens in the optical machine, and the shift change of the projected picture caused by the shift of the lens optical system is much larger than that caused by directly shifting the optical machine to the same size. Generally, the optical shift axis of the projection optical machine includes a horizontal shift axis and a vertical shift axis, fig. 5a is a schematic diagram of the optical horizontal shift axis, where 51 denotes the projection optical machine, 52 denotes the projection surface, 53 denotes the original projection picture of the projection optical machine on the projection surface, and 54 denotes the projection picture of the projection optical machine on the projection surface after the horizontal shift axis, which realizes the large displacement of the projection picture in the horizontal direction by the optical shift axis system; fig. 5b is a schematic diagram of optical vertical shift, in which 51 denotes a projection engine, 52 denotes a projection plane, 53 denotes an original projection picture of the projection engine on the projection plane, and 55 denotes a projection picture of the projection engine on the projection plane after vertical shift, which realizes a large shift of the projection picture in the vertical direction by the optical shift system. The optical shift system can realize the physical displacement of an optical imaging picture under the condition that the position of a projection optical machine is not fixed by the precise movement of a complex optical lens group, thereby having no influence on the image quality and the brightness, and being a lossless picture processing technology.
In some optional embodiments of the present application, an offset required to perform optical shift when adjusting a projection picture of a projection optics machine to a target projection area may be determined according to the first angle information, and the optical shift may be performed on the projection optics machine according to the offset, where the offset includes a horizontal offset in a horizontal direction and a vertical offset in a vertical direction.
Specifically, a second corresponding relationship between the rotation angle of the projection light engine (i.e., the rotation angle of the rotation mechanism) and the offset of the optical shift axis may be determined; according to the second corresponding relation and the first angle information, when the projection picture of the projection optical machine is adjusted to the target projection area, the offset of optical shift is determined, and the horizontal offset can be determined according to the second corresponding relation and the horizontal rotation angle; and determining the vertical offset according to the second corresponding relation and the vertical pitch angle.
As shown in fig. 6, 61 denotes a projection optical machine, 62 denotes a projection surface, 63 denotes a trapezoidal projection picture of the projection optical machine in the target projection area of the projection surface, 64 denotes a rectangular projection picture of the projection optical machine on the projection surface after being adjusted by a rotation mechanism, a distance L between the two is a final picture offset of horizontal shift axis, since an angle Ang _ H of horizontal rotation of the projection optical machine and a final picture offset L of horizontal shift axis have a relationship similar to a right triangle, the final picture offset L of horizontal shift axis and a rotation angle Ang _ H are in a proportional linear relationship, on the basis, a data table between Ang _ H and a horizontal shift axis motor offset Len _ H of the optical machine can be established, and the data table can be obtained by collecting corresponding optical shift axis motor offset steps obtained from different angles, i.e. Len _ H ═ a _ Ang _ H + b, the a and the b are obtained by combining the design of a projection optical machine and the calculation and fitting of the actual motion effect of the optical shift motor; alternatively, considering that the actual image shift amount of the optical shift axis may have an error rather than absolute linearity in the motor motion interval, enough data may be collected to fit through an actual nonlinear relationship, i.e., Len _ H ═ f (Ang _ H). Similarly, the corresponding relationship between the offset Len _ V of the optical machine vertical shift motor and the angle Ang _ V of the projection optical machine vertical rotation can also be obtained: len _ V ═ c × Ang _ V + d or Len _ V ═ f (Ang _ V).
Finally, performing optical horizontal shift on the projection optical machine according to the horizontal offset Len _ H; and performing optical vertical shift on the projection optical machine according to the vertical offset Len _ H, so as to adjust the position of the projection picture and enable the projection picture to be projected in the target projection area.
Generally, a projection optical machine has a digital correction function, changes the position of a projected picture pixel through a software algorithm, and has two modes of manual operation and automatic operation, wherein a user manually calls a correction setting menu, and adjusts the picture shape by manually controlling the positions of a plurality of vertexes of a projected picture; the automatic mode is that the projection plane information is collected through an image collecting module, and the picture is automatically corrected into a rectangle through automatic compensation of the projection position.
In some optional embodiments of the present application, after the rotating mechanism is controlled to rotate according to the first angle information, a correction instruction of the target object may be received, and the projection picture may be corrected according to the correction instruction, where the correction instruction is used to instruct to correct the projection picture again through a digital correction function.
It can be understood that the optical projection engine can correct the projection image according to the projection correction method, and can also correct the projection image through a digital correction function. For example, when the rotation mechanism fails to perform automatic correction on the projection image, or the user is still unsatisfied with the corrected projection image, the user can receive the instruction from the user and correct the projection image again by the digital correction function according to the instruction from the user.
In an alternative embodiment of the present application, a complete process for correcting the projection picture is shown in fig. 7:
1) acquiring projection picture/projection plane depth information through an image acquisition module;
2) calculating three-dimensional point cloud information and picture coordinate information of a projection surface according to the acquired image or depth information;
3) performing plane fitting according to the three-dimensional point cloud information and the picture coordinate information to obtain a plane equation of the projection plane;
4) calculating the horizontal rotation angle Ang _ H of the projection light machine according to a plane equation;
5) determining a vertical pitching angle Ang _ V of a projection light machine according to a plane equation or an IMU attitude sensor;
6) determining the inclination angle Ang _ Z of the projection light machine according to the IMU attitude sensor;
7) determining the direction and the number of the rotation steps of the motor according to the first corresponding relation between the number of the rotation steps of the motor and the rotation angle and the determined Ang _ H, Ang _ V, Ang _ Z;
8) controlling a motor to drive a rotating mechanism to rotate according to the determined rotating direction and the determined rotating steps;
9) and finishing physical correction of the projection picture, wherein the projection picture in the projection area is rectangular finally, and no image quality loss or gray edge caused by digital correction exists.
In the embodiment of the application, by acquiring the projection information and the posture information of the optical projection engine, determining first angle information when the rotating mechanism rotates, and rotating the rotating mechanism according to the first angle information, so that the projection direction of the optical projection engine is adjusted to be opposite to a projection surface, and a projection picture with trapezoidal distortion originally is corrected to be rectangular; and calculating the offset of the optical shift axis according to the first angle information and performing the optical shift axis on the projection light machine, so that the projection picture is projected to the target projection area. Since the projection picture is corrected by adjusting the projection direction of the projection light machine in the embodiment of the application, the scaling of the projection picture is not involved, and therefore the technical problems of image quality loss and gray edge effect existing in the correction of the projection picture in the related technology can be effectively solved.
Example 2
According to an embodiment of the present application, there is also provided a projection keystone correction apparatus for implementing the projection keystone correction method described above, as shown in fig. 8, the apparatus includes a first obtaining module 80, a second obtaining module 82, a first determining module 84, and a rotating module 86, where:
the first obtaining module 80 is configured to obtain projection information of the projection light engine.
In some optional embodiments of the present application, the projection information of the projection light engine may be acquired by an image acquisition module, where the image acquisition module includes at least one of: the camera module and the depth information measuring module are arranged on the camera module; the projection information includes at least one of: projection picture information, feature map information, depth information of the projection plane.
And a second obtaining module 82, configured to obtain pose information of the projection optical machine.
In some optional embodiments of the present application, the attitude information of the light projector engine may be obtained by an attitude sensor, such as a gyroscope or other gravity sensor, and the attitude information at least includes an inclination angle between the light projector engine and a horizontal plane.
The first determining module 84 is configured to determine, according to the projection information and the posture information, first angle information that the rotating mechanism needs to rotate when the projection direction of the optical projection engine is adjusted to be opposite to the projection plane, where the projection plane is a plane where the projection picture is located.
In some optional embodiments of the present application, three-dimensional point cloud information and image coordinate information of a projection surface are determined according to acquired projection information such as projection image information or projection surface depth information; performing plane fitting according to the obtained three-dimensional point cloud information and the picture coordinate information to obtain a plane equation of the projection plane; determining a horizontal rotation angle of the rotating mechanism in the horizontal direction when the projection direction of the projector is adjusted to be opposite to the projection plane according to a plane equation; determining a vertical pitch angle of the rotating mechanism in the vertical direction when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to a plane equation or the posture information of the projection optical machine; determining the inclination angle of the projection light machine according to the attitude information; the horizontal rotation angle, the vertical pitch angle, and the tilt angle are taken as first angle information.
And a rotating module 86, configured to control the rotating mechanism to rotate according to the first angle information.
In some optional embodiments of the present application, since the rotating mechanism is driven to rotate by the motor, a first corresponding relationship between the number of steps of the motor and the rotation angle of the rotating mechanism may be determined; then, determining the direction in which the motor needs to rotate and the number of rotating steps in the corresponding direction according to the first corresponding relation and the first angle information; and then the motor is controlled to drive the rotating mechanism to rotate according to the rotating direction and the rotating steps.
It should be noted that, in the embodiment of the present application, each module in the projection keystone correction apparatus corresponds to the implementation step of the projection keystone correction method in embodiment 1 one to one, and since the detailed description is already performed in embodiment 1, details that are not partially reflected in this embodiment may refer to embodiment 1, and are not described herein again.
Example 3
According to an embodiment of the application, a non-volatile storage medium is further provided, and the non-volatile storage medium includes a stored program, wherein the device where the non-volatile storage medium is located is controlled to execute the projection trapezoidal correction method when the program runs.
Optionally, the apparatus in which the non-volatile storage medium is controlled when the program is running executes the following steps: acquiring projection information of a projection optical machine; acquiring attitude information of a projection optical machine; determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located; and controlling the rotating mechanism to rotate according to the first angle information.
The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.
In the above embodiments of the present application, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.
In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, a division of a unit may be a division of a logic function, and an actual implementation may have another division, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or may not be executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.
The foregoing is only a preferred embodiment of the present application and it should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.
Claims (10)
1. A projection keystone correction method is applied to a projection system, and the projection system at least comprises: a light engine and a rotation mechanism for adjusting a projection direction of the light engine, the method comprising:
acquiring projection information of the projection optical machine;
acquiring attitude information of the projection optical machine;
determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located;
and controlling the rotating mechanism to rotate according to the first angle information.
2. The method of claim 1, wherein obtaining projection information of the projection light engine comprises:
acquiring projection information of the projection light machine through an image acquisition module, wherein the image acquisition module comprises at least one of the following components: the camera module and the depth information measuring module are arranged on the camera module; the projection information includes at least one of: projection picture information, feature map information and depth information of the projection plane.
3. The method of claim 2, wherein obtaining pose information of the projector engine comprises:
acquiring the attitude information of the projection light machine through an attitude sensor, wherein the attitude information at least comprises the attitude angle information of the projection light machine.
4. The method of claim 3, wherein determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projector light engine is adjusted to face the projection plane according to the projection information and the pose information comprises:
determining 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 a plane equation of the projection plane and a normal vector of the plane equation;
determining a horizontal rotation angle according to the plane equation and the normal vector, wherein the horizontal rotation angle is an angle of the rotation mechanism rotating in the horizontal direction when the projection direction of the projection light machine is adjusted to be opposite to the projection plane;
determining a vertical pitch angle according to the plane equation and the normal vector, or determining the vertical pitch angle according to the attitude angle information, wherein the vertical pitch angle is an angle of the rotating mechanism rotating in the vertical direction when the projection direction of the projection light machine is adjusted to be opposite to the projection plane;
determining an inclination angle of the projection optical machine according to the attitude angle information, wherein the inclination angle is an angle of rotation of the rotating mechanism when the projection optical machine is adjusted to be parallel to a horizontal plane;
taking the horizontal rotation angle, the vertical pitch angle, and the tilt angle as the first angle information.
5. The method according to claim 1, wherein the rotating mechanism is driven to rotate by a motor, and the rotating mechanism is controlled to rotate according to the first angle information, and the method comprises the following steps:
determining a first corresponding relationship between the number of rotation steps of the motor and the rotation angle of the rotating mechanism;
determining the direction in which the motor needs to rotate and the number of rotation steps in the corresponding direction according to the first corresponding relation and the first angle information;
and controlling the motor to drive the rotating mechanism to rotate according to the rotating direction and the rotating steps.
6. The method of claim 1, wherein the projection light engine supports an optical shift function, and after controlling the rotation mechanism to rotate according to the first angle information, the method further comprises:
and determining the offset required for optical shift when the projection picture of the projection optical machine is adjusted to a target projection area according to the first angle information, and performing optical shift on the projection optical machine according to the offset, wherein the offset comprises a horizontal offset in the horizontal direction and a vertical offset in the vertical direction.
7. The method according to claim 1, wherein the projector has a digital correction function, and after controlling the rotation mechanism to rotate according to the first angle information, the method further comprises:
and receiving a correction instruction of a target object, and correcting the projection picture according to the correction instruction, wherein the correction instruction is used for indicating that the projection picture is corrected again through the digital correction function.
8. A projection keystone correction apparatus, comprising:
the first acquisition module is used for acquiring projection information of the projection light machine;
the second acquisition module is used for acquiring the attitude information of the projection optical machine;
the first determining module is used for determining first angle information that the rotating mechanism needs to rotate when the projection direction of the projection optical machine is adjusted to be opposite to the projection plane according to the projection information and the posture information, wherein the projection plane is a plane where a projection picture is located;
and the rotating module is used for controlling the rotating mechanism to rotate according to the first angle information.
9. A projection system, comprising:
the projection light machine is used for projecting the projection picture to a target projection area;
the image acquisition module is used for acquiring projection information of the projection light machine;
the attitude information acquisition module is used for acquiring attitude information of the projection optical machine, and the attitude information at least comprises attitude angle information of the projection optical machine;
the calculation processing module is used for determining first angle information which is required to rotate by the rotation module when the projection direction of the projection optical machine is adjusted to be opposite to the projection surface according to the projection information and the posture information;
and the rotating module is used for adjusting the projection direction of the projection optical machine to be opposite to the projection surface according to the first angle information.
10. A non-volatile storage medium, comprising a stored program, wherein the program, when executed, controls a device in which the non-volatile storage medium is located to perform the projection keystone correction method of any one of claims 1 to 8.
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