Calibration parameter acquisition method and device of projection equipment and computer equipment

Abstract

The invention provides a calibration parameter acquisition method and device of projection equipment and computer equipment. Comprising the following steps: acquiring a unit rotation matrix of an inertial measurement unit, and shooting first two-dimensional information and second two-dimensional information obtained by a calibration plate by a camera device and a projection camera when to-be-calibrated projection equipment rotates at a plurality of preset angles along with a rotary table for projection; obtaining corresponding first three-dimensional information according to the first two-dimensional information; obtaining a second rotation matrix of the camera equipment coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information; obtaining a projection plane normal vector under a projection camera coordinate system according to the projection plane normal vector under the camera equipment coordinate system and the second rotation matrix; and according to the projection plane normal vector of the rotary table coordinate system, the unit rotation matrix, the projection plane normal vector of the inertial measurement unit coordinate system and the projection plane normal vector of the projection camera coordinate system, obtaining external parameter data of the projection camera and the inertial measurement unit of the projection equipment to be calibrated.

Description

Technical Field

[0001] The present application relates to the technical field of parameter acquisition of projection equipment, and in particular to a method, device and computer equipment for acquiring calibration parameters of a projection equipment. Background Art

[0002] In order to improve the stability of the projection screen of the projection device, the projection device has added functions such as trapezoidal correction and automatic obstacle avoidance, and the above functions need to be realized through the inertial measurement unit and projection camera carried by the projection device. Among them, the parameter calibration of the inertial measurement unit and projection camera affects the accuracy of functions such as trapezoidal correction and automatic obstacle avoidance, and the relevant technology has the technical defect of being unable to accurately calibrate the parameters of the inertial measurement unit and projection camera of the projection device. Summary of the invention

[0003] The purpose of the present application is to overcome the shortcomings and deficiencies in the prior art and to provide a method, device and computer equipment for obtaining calibration parameters of a projection device, which can accurately obtain the external parameter data of a projection camera and an inertial measurement unit of the projection device to be calibrated.

[0004] A first aspect of an embodiment of the present application provides a method for obtaining calibration parameters of a projection device, which is applied to a calibration system, wherein the calibration system includes a projection device to be calibrated, a turntable, and a camera device; the projection device to be calibrated is arranged on the turntable; the projection device to be calibrated includes a projection camera and an inertial measurement unit; the method includes:

[0005] Obtaining a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; obtaining a unit rotation matrix of the inertial measurement unit according to the first rotation matrix;

[0006] Acquire first two-dimensional information of the calibration plate on the projection plane obtained by the camera device and second two-dimensional information of the calibration plate obtained by the projection camera when the projection device to be calibrated rotates to a plurality of preset angles for projection as the turntable rotates; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system;

[0007] Obtaining first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; obtaining a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information;

[0008] Obtaining a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information;

[0009] Obtaining a projection plane normal vector in a projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix;

[0010] According to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system, the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated are obtained.

[0011] A second aspect of an embodiment of the present application provides a device for obtaining calibration parameters of a projection device, which is applied to a calibration system, wherein the calibration system comprises a projection device to be calibrated, a turntable and a camera device; the projection device to be calibrated is arranged on the turntable; the projection device to be calibrated comprises a projection camera and an inertial measurement unit;

[0012] The device comprises:

[0013] A first rotation matrix acquisition module is used to acquire a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; and obtain a unit rotation matrix of the inertial measurement unit according to the first rotation matrix;

[0014] A two-dimensional information acquisition module, used for acquiring first two-dimensional information obtained by the camera device photographing the calibration plate on the projection plane and second two-dimensional information obtained by the projection camera photographing the calibration plate when the projection device to be calibrated rotates to a plurality of preset angles for projection as the turntable rotates; wherein the first two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system;

[0015] A first normal vector acquisition module, used to obtain first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; and obtain a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information;

[0016] A second rotation matrix acquisition module, used for obtaining a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information;

[0017] A second normal vector acquisition module, used to obtain the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix;

[0018] The external parameter data acquisition module is used to obtain the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system.

[0019] A third aspect of an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the steps of the method for obtaining calibration parameters of the projection device as described above when executing the computer program.

[0020] Compared with the related art, the calibration system used in the present application includes a projection device to be calibrated, a turntable and a camera device, and the projection device to be calibrated is arranged on the turntable. When the projection device to be calibrated rotates with the turntable to project at multiple preset angles, the first two-dimensional information obtained by the camera device shooting the calibration plate on the projection plane and the second two-dimensional information obtained by the projection camera shooting the calibration plate are obtained, and then the first three-dimensional information of each feature point in the camera device coordinate system is obtained according to the two-dimensional information of each feature point in the camera device coordinate system, and then the first three-dimensional information of each feature point in the camera device coordinate system is obtained according to the first two-dimensional information, so as to obtain the second rotation matrix of the camera device coordinate system and the projection camera coordinate system by using the first three-dimensional information and the second two-dimensional information, and the projection plane normal vector in the projection camera coordinate system is obtained according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix, and then the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated are obtained according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system, thereby achieving the technical effect of accurately obtaining the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated.

[0021] In order to provide a clearer understanding of the present application, the specific implementation of the present application will be described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a method for obtaining calibration parameters of a projection device according to an embodiment of the present application.

[0023] Figure 2 A schematic diagram of parameter relationships of a method for obtaining calibration parameters of a projection device according to an embodiment of the present application.

[0024] Figure 3 A schematic diagram of module connections of a calibration parameter acquisition device for a projection device according to an embodiment of the present application.

[0025] 100. Calibration parameter acquisition device of projection equipment; 101. First rotation matrix acquisition module; 102. Two-dimensional information acquisition module; 103. First normal vector acquisition module; 104. Second rotation matrix acquisition module; 105. Second normal vector acquisition module; 106. External parameter data acquisition module. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0027] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0028] When the following description relates to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. The singular forms of "a", "said" and "the" used in the present application and the appended claims are also intended to include the majority form, unless the context clearly indicates other meanings. The words "if" / "if" used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0029] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0030] The present application is applied to a calibration system, which includes a projection device to be calibrated, a turntable and a camera device. The projection device to be calibrated is arranged on the turntable. The projection device to be calibrated includes a projection camera and an inertial measurement unit.

[0031] Among them, the projection device to be calibrated is a device that forms a projection picture by radiating light, and the projection device to be calibrated includes a projection optical machine, a projection camera and an inertial measurement unit. Among them, the normal vectors of the projection plane under the coordinate system of the inertial measurement unit are all (1,0,0), and the external parameter data of the projection camera and the inertial measurement unit belong to the data to be calibrated. In order to accurately obtain the data to be calibrated, this application uses a projection plane as a reference plane, and the projection plane can be a wall or a curtain. Specifically, the projection plane is covered with a calibration plate, and the external parameter data of the projection camera and the inertial measurement unit are calibrated with the help of the feature points of the calibration plate and the projection picture of the projection device to be calibrated. Among them, the calibration plate is a geometric model with a fixed-spacing pattern array, which is often used to determine the relationship between the three-dimensional geometric position of a point on the surface of a spatial object and its corresponding point in the image.

[0032] A turntable refers to a rotatable carrier that can only rotate but not translate. The turntable is used to carry the projection device to be calibrated. Since the projection device to be calibrated is set on the turntable, the projection device to be calibrated will rotate with the rotation of the turntable, resulting in a change in the angle of the projection device to be calibrated relative to the projection plane. The state of the turntable when the projection device to be calibrated faces the preset projection plane is determined as a zero-position state. The turntable coordinate system corresponding to the turntable in the zero-position state is consistent with the unit coordinate system of the inertial measurement unit. The corresponding rotation matrix when the turntable rotates is the same as the rotation matrix of the inertial measurement unit. At this time, the projection plane normal vector in the turntable coordinate system corresponding to the turntable in the zero-position state and the projection plane normal vector in the inertial measurement unit coordinate system are both (1,0,0).

[0033] The camera device is a shooting device external to the projection device to be calibrated. This application will use the projection image of the projection device to be calibrated and the image of the calibration plate taken by the camera device to obtain the external parameter data of the projection camera and the inertial measurement unit. Among them, the camera device and the projection device are located on the same vertical plane parallel to the projection plane, which can reduce the impact of spatial position synchronization on the calibration result.

[0034] See also Figure 1 , which is a method for obtaining calibration parameters of a projection device according to an embodiment of the present application, comprising:

[0035] S1: Obtain a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; obtain a unit rotation matrix of the inertial measurement unit according to the first rotation matrix.

[0036] Among them, the turntable facing the projection plane means that the projection device on the turntable faces the projection plane, and the projection direction of the projection device is perpendicular to the projection plane. Multiple angles refer to the angles of rotation in multiple directions with the turntable facing the projection plane at zero position, and the rotation angles in each direction are the same. For example, the turntable is controlled to turn 15 degrees to the right, 15 degrees to the upper right, 15 degrees to the upper left, and 15 degrees to the left, etc., wherein each steering angle can be regarded as a point state of the turntable. Under different point states, the projection images projected by the projection device onto the calibration plate of the projection plane are different.

[0037] S2: When the projection device to be calibrated rotates with the turntable to project at multiple preset angles, the camera device obtains the first two-dimensional information of the calibration plate on the projection plane and the projection camera obtains the second two-dimensional information of the calibration plate; wherein the first two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system.

[0038] Among them, since the camera device coordinate system is different from the projection camera coordinate system, the first two-dimensional information and the second two-dimensional information corresponding to the same feature point on the calibration plate are also different.

[0039] S3: Obtain first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; obtain a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information.

[0040] Among them, by performing plane fitting on the first three-dimensional information, the plane equation corresponding to the projection plane normal vector in the camera device coordinate system can be obtained. The plane equation is as follows:

[0041] Ax+By+Cz+1=0;

[0042] Among them, A, B and C are the projection plane normal vectors in the camera device coordinate system, and x, y and z are the first three-dimensional information corresponding to the feature point.

[0043] S4: Obtain a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information.

[0044] Among them, the calibrateCamera function of opencv can be used to calibrate the camera according to the first three-dimensional information and the second two-dimensional information, so as to obtain the intrinsic parameters of the projection camera and the extrinsic parameter data of the camera device and the projection camera, wherein the extrinsic parameter data from the camera device to the projection camera includes the second rotation matrix of the camera device and the projection camera, and the translation matrix of the camera device and the projection camera. Among them, opencv is an open source cross-platform computer vision and machine learning software library, and the calibrateCamera function can solve the intrinsic parameters of the camera and the extrinsic parameters of each perspective through the 2D / 3D correspondence of multiple perspectives.

[0045] S5: Obtain the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix.

[0046] S6: Obtain the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system, and the projection plane normal vector in the projection camera coordinate system.

[0047] Compared with the related art, the calibration system used in the present application includes a projection device to be calibrated, a turntable and a camera device, and the projection device to be calibrated is arranged on the turntable. When the projection device to be calibrated rotates with the turntable to project at multiple preset angles, the first two-dimensional information obtained by the camera device shooting the calibration plate on the projection plane and the second two-dimensional information obtained by the projection camera shooting the calibration plate are obtained, and then the first three-dimensional information of each feature point in the camera device coordinate system is obtained according to the two-dimensional information of each feature point in the camera device coordinate system, and then the first three-dimensional information of each feature point in the camera device coordinate system is obtained according to the first two-dimensional information, so as to obtain the second rotation matrix of the camera device coordinate system and the projection camera coordinate system by using the first three-dimensional information and the second two-dimensional information, and the projection plane normal vector in the projection camera coordinate system is obtained according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix, and then the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated are obtained according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system, thereby achieving the technical effect of accurately obtaining the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated.

[0048] In a feasible embodiment, step S2: when the projection device to be calibrated rotates with the turntable to project at multiple preset angles, the camera device captures the calibration plate on the projection plane to obtain the first two-dimensional information, including:

[0049] S201: Acquire a first calibration plate photographed image obtained when a camera device photographs a calibration plate laid on a projection plane.

[0050] S202: Perform feature point detection on the image captured by the first calibration plate to obtain third two-dimensional information of the feature points of the calibration plate in the camera device coordinate system; wherein the third two-dimensional information corresponds to.

[0051] S203: Acquire a first projected captured image obtained when the camera device projects the projection device to be calibrated as the turntable rotates to a plurality of preset angles.

[0052] S204: Identify a screen range of the projection screen in the first projection captured image, and determine the third two-dimensional information located in the screen range as the first two-dimensional information.

[0053] In this embodiment, the first two-dimensional information for calculating the projection plane normal vector in the camera device coordinate system may be acquired according to the image range of the projection image in the first projection captured image.

[0054] In a feasible embodiment, S3: the step of obtaining first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system includes:

[0055] The first three-dimensional information of each feature point in the camera device coordinate system is obtained according to the first two-dimensional information and the three-dimensional information of the feature point corresponding to the first two-dimensional information on the calibration plate.

[0056] Among them, the 3D information of the feature points on the calibration plate is known information. The PnP algorithm of opencv can be used to calculate the first 3D information of each feature point in the camera device coordinate system based on the first 2D information and the 3D information of the feature points on the calibration plate corresponding to the first 2D information. The full name of the PnP algorithm is Perspective-n-Point, which is a method for solving the correspondence between 3D and 2D points.

[0057] In this embodiment, the first three-dimensional information corresponding to the first two-dimensional information can be calculated based on the first two-dimensional information and the three-dimensional information of the feature points corresponding to the first two-dimensional information on the calibration plate, so as to accurately obtain the first three-dimensional information of each feature point in the camera device coordinate system.

[0058] In a feasible embodiment, step S2: obtaining the second two-dimensional information of the calibration plate obtained by the projection camera when the projection device to be calibrated rotates with the turntable to project at multiple preset angles, comprises:

[0059] S211: Acquire a second calibration plate photographed image obtained when a projection camera photographs the calibration plate laid on the projection plane.

[0060] S212: Perform feature point detection on the image captured by the second calibration plate to obtain fourth two-dimensional information of the feature points of the calibration plate in the projection camera coordinate system.

[0061] S213: Acquire a second projection captured image obtained when the projection camera photographs the projection device to be calibrated as the turntable rotates to a plurality of preset angles.

[0062] S214: Identify a screen range of the projection screen in the second projected captured image, and determine the fourth two-dimensional information located in the screen range as the second two-dimensional information.

[0063] In this embodiment, second two-dimensional information for calculating a second rotation matrix of a camera device coordinate system and a projection camera coordinate system may be acquired according to the picture range of the projection picture in the second projection captured image.

[0064] In a feasible embodiment, S5: the step of obtaining the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix includes:

[0065] The second rotation matrix is ​​matrix-multiplied by the projection plane normal vector in the camera device coordinate system to obtain the projection plane normal vector in the projection camera coordinate system.

[0066] The calculation of the projection plane normal vector in the projection camera coordinate system is shown in the following formula:

[0067] n_cam=R_cam_fixed*n_fixed;

[0068] Among them, n_cam is the projection plane normal vector in the projection camera coordinate system, R_cam_fixed is the second rotation matrix, and n_fixed is the projection plane normal vector in the camera device coordinate system.

[0069] See also Figure 2 In this embodiment, the projection plane normal vector in the camera device coordinate system can be transformed into the projection plane normal vector in the camera device coordinate system through the second rotation matrix. Therefore, according to the second rotation matrix of the camera device coordinate system and the projection camera coordinate system, and the projection plane normal vector in the camera device coordinate system, the projection plane normal vector in the projection camera coordinate system can be calculated.

[0070] In a feasible embodiment, step S6: the step of obtaining the external parameter data of the projection camera and the inertial measurement unit according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system, and the projection plane normal vector in the projection camera coordinate system includes:

[0071] S61: Construct a first objective function by taking the external parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, and the projection plane normal vector in the inertial measurement unit coordinate system as input and the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated as output.

[0072] Among them, step S61 includes: performing matrix multiplication on the external parameter data, the first rotation matrix and the projection plane normal vector in the inertial measurement unit coordinate system, and taking the projection plane normal vector in the actual projection camera coordinate system as the product of the matrix multiplication to obtain the first objective function.

[0073] That is, the first objective function is shown in the following formula:

[0074] n_cam_estimate=R_cam_base*R_base_pose0*n_pose0;

[0075] Among them, n_cam_estimate is the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated, R_cam_base is the external parameter data of the projection camera and the inertial measurement unit, R_base_pose0 is the first rotation matrix, and n_pose0 is the projection plane normal vector in the inertial measurement unit coordinate system.

[0076] S62: Construct a second objective function according to the projection plane normal vector in the actual projection camera coordinate system, the projection plane normal vector in the projection camera coordinate system, and the angle between the projection plane normal vector in the actual projection camera coordinate system and the projection plane normal vector in the projection camera coordinate system.

[0077] The second objective function is as follows:

[0078] f(R_cam_base)=n_cam_estimate*n_cam*cosθ;

[0079] Among them, n_cam_estimate and n_cam in the above formula are both unit vectors, and θ is the angle between the normal vector of the projection plane in the actual projection camera coordinate system and the normal vector of the projection plane in the projection camera coordinate system. Among them, when the angle in the second objective function is closer to 0, the accuracy of the external parameter data of the corresponding projection camera and the inertial measurement unit is the highest. When the angle in the second objective function cannot be equal to 0, the closer the angle is to 0, the accuracy of the external parameter data of the corresponding projection camera and the inertial measurement unit is the highest.

[0080] S63: Obtaining external parameter data of the projection camera and the inertial measurement unit according to the second objective function.

[0081] In this embodiment, according to the second objective function, the external parameter data of the projection camera and the inertial measurement unit can be inverted when the projection plane normal vector in the actual projection camera coordinate system is closest to the calculated projection plane normal vector in the projection camera coordinate system, thereby obtaining the external parameter data of the projection camera and the inertial measurement unit with high accuracy.

[0082] In a feasible embodiment, the projection device to be calibrated includes a projection light machine, and the projection screen of the projection light machine is a calibration image; the calibration image is an image of a geometric model with a fixed-pitch pattern array, for example, it can be an image of a calibration plate. The fixed-pitch pattern array of the calibration image can be different from the fixed-pitch pattern array of the calibration plate laid on the projection plane.

[0083] The method for obtaining calibration parameters of the projection device also includes:

[0084] S71: Acquire two-dimensional feature point information of feature points of the calibration image and three-dimensional feature point information of feature points of the calibration image on the calibration plate.

[0085] S72: Acquire the internal parameter data of the projection camera, the internal parameter data of the projection optical machine, and the external parameter data of the projection camera and the projection optical machine according to the second two-dimensional information, the two-dimensional feature point information, and the feature point three-dimensional information.

[0086]

[0087] Among them, K_cam is the internal parameter data of the projection camera, K_proj is the internal parameter data of the projection optical machine, R_proj_cam, t_proj_cam are the external parameter data of the projection camera and the projection optical machine, p_ij is the three-dimensional corner point data of the j-th corner point of the projection picture at the i-th preset angle, z_cij is the second two-dimensional coordinate point data, and z_pij is the two-dimensional corner point data.

[0088] In this embodiment, through steps S71-S72, the internal parameter data of the projection camera, the internal parameter data of the projection optical machine, and the external parameter data of the projection camera and the projection optical machine can also be obtained to obtain more calibration parameters of the projection device.

[0089] See also Figure 3 The second embodiment of the present application provides a calibration parameter acquisition device 100 for a projection device, which is applied to a calibration system. The calibration system includes a projection device to be calibrated, a turntable and a camera device; the projection device to be calibrated is arranged on the turntable; the projection device to be calibrated includes a projection camera and an inertial measurement unit;

[0090] The device includes:

[0091] A first rotation matrix acquisition module 101 is used to acquire a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; and obtain a unit rotation matrix of the inertial measurement unit according to the first rotation matrix;

[0092] The two-dimensional information acquisition module 102 is used to acquire the first two-dimensional information obtained by the camera device photographing the calibration plate on the projection plane and the second two-dimensional information obtained by the projection camera photographing the calibration plate when the projection device to be calibrated rotates to the preset multiple angles for projection along with the turntable; wherein the first two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system;

[0093] A first normal vector acquisition module 103 is used to obtain first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; and obtain a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information;

[0094] A second rotation matrix acquisition module 104, used to obtain a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information;

[0095] A second normal vector acquisition module 105 is used to obtain the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix;

[0096] The external parameter data acquisition module 106 is used to obtain the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated based on the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system, and the projection plane normal vector in the projection camera coordinate system.

[0097] It should be noted that the calibration parameter acquisition device 100 for a projection device provided in the second embodiment of the present application only uses the division of the above-mentioned functional modules as an example when executing the calibration parameter acquisition method for a projection device. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the calibration parameter acquisition device 100 for a projection device provided in the second embodiment of the present application and the calibration parameter acquisition method for a projection device in the first embodiment of the present application are of the same concept. The implementation process thereof is detailed in the method embodiment and will not be repeated here.

[0098] A third aspect of an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable by the processor. When the processor executes the computer program, the steps of the method for obtaining calibration parameters of the projection device as described above are implemented.

[0099] The device embodiments described above are merely illustrative, wherein the components described as separate parts may or may not be physically separated, and the parts displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application. Ordinary technicians in this field can understand and implement it without creative work.

[0100] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0101] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the function selected in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 function selected in a box or multiple boxes.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 steps for the function selected in a box or multiple boxes.

[0103] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0104] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0105] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0106] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0107] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for obtaining calibration parameters of a projection device, characterized in that: Applied to a calibration system, the calibration system comprises a projection device to be calibrated, a turntable and a camera device; the projection device to be calibrated is arranged on the turntable; The projection device to be calibrated includes a projection camera and an inertial measurement unit; the method includes: Obtaining a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; obtaining a unit rotation matrix of the inertial measurement unit according to the first rotation matrix; Acquire first two-dimensional information of the calibration plate on the projection plane obtained by the camera device and second two-dimensional information of the calibration plate obtained by the projection camera when the projection device to be calibrated rotates to a plurality of preset angles for projection as the turntable rotates; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system; Obtaining first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; obtaining a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information; Obtaining a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information; Obtaining a projection plane normal vector in a projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix; According to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system, the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated are obtained.

2. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The step of obtaining the external parameter data of the projection camera and the inertial measurement unit according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system comprises: Taking the external parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, and the projection plane normal vector in the inertial measurement unit coordinate system as input, and taking the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated as output, a first objective function is constructed; constructing the second objective function according to the projection plane normal vector in the actual projection camera coordinate system, the projection plane normal vector in the projection camera coordinate system, and the angle between the projection plane normal vector in the actual projection camera coordinate system and the projection plane normal vector in the projection camera coordinate system; According to the second objective function, external parameter data of the projection camera and the inertial measurement unit are obtained.

3. The method for obtaining calibration parameters of a projection device according to claim 2, characterized in that: The step of constructing a first objective function by taking the external parameter data to be acquired of the projection camera and the inertial measurement unit, the first rotation matrix, and the projection plane normal vector in the inertial measurement unit coordinate system as input, and taking the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated as output, comprises: The extrinsic parameter data, the first rotation matrix and the projection plane normal vector in the inertial measurement unit coordinate system are matrix multiplied, and the projection plane normal vector in the actual projection camera coordinate system is used as the product of the matrix multiplication to obtain the first objective function.

4. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The step of obtaining the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix comprises: The second rotation matrix is ​​matrix-multiplied by the projection plane normal vector in the camera device coordinate system to obtain the projection plane normal vector in the projection camera coordinate system.

5. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The step of obtaining the first two-dimensional information obtained by the camera device photographing the calibration plate on the projection plane when the projection device to be calibrated rotates with the turntable to project at multiple preset angles comprises: Acquire a first calibration plate photographed image obtained when the camera device photographs the calibration plate laid on the projection plane; Performing feature point detection on the image captured by the first calibration plate to obtain third two-dimensional information of the feature points of the calibration plate in the camera device coordinate system; wherein the third two-dimensional information corresponds to; Acquire a first projection captured image obtained when the camera device projects the projection device to be calibrated as the turntable rotates to a plurality of preset angles; A screen range of a projection screen in the first projection captured image is identified, and third two-dimensional information located in the screen range is determined as the first two-dimensional information.

6. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The step of obtaining first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system comprises: According to the first two-dimensional information and the three-dimensional information of the feature points corresponding to the first two-dimensional information on the calibration plate, the first three-dimensional information of each of the feature points in the camera device coordinate system is obtained.

7. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The step of obtaining the second two-dimensional information obtained by the projection camera photographing the calibration plate when the projection device to be calibrated performs projection along with the turntable turning to the preset multiple angles comprises: Acquire a second calibration plate photographed image obtained when the projection camera photographs the calibration plate laid on the projection plane; Performing feature point detection on the image captured by the second calibration plate to obtain fourth two-dimensional information of the feature points of the calibration plate in the projection camera coordinate system; Acquire a second projection captured image obtained when the projection camera photographs the projection device to be calibrated as the turntable rotates to a plurality of preset angles; A screen range of a projection screen in the second projection captured image is identified, and fourth two-dimensional information located in the screen range is determined as the second two-dimensional information.

8. The method for obtaining calibration parameters of a projection device according to claim 1, characterized in that: The projection device to be calibrated includes a projection optical machine, and the projection picture of the projection optical machine is a calibration image; The method further comprises the following steps: Acquire two-dimensional feature point information of feature points of the calibration image and three-dimensional feature point information of the feature points of the calibration image on the calibration plate; According to the second two-dimensional information, the two-dimensional feature point information and the three-dimensional feature point information, the internal parameter data of the projection camera, the internal parameter data of the projection light machine, and the external parameter data of the projection camera and the projection light machine are obtained.

9. A device for obtaining calibration parameters of a projection device, characterized in that: Applied to a calibration system, the calibration system comprises a projection device to be calibrated, a turntable and a camera device; the projection device to be calibrated is arranged on the turntable; the projection device to be calibrated comprises a projection camera and an inertial measurement unit; The device comprises: A first rotation matrix acquisition module is used to acquire a first rotation matrix of the turntable from facing the projection plane to a plurality of preset angles; and obtain a unit rotation matrix of the inertial measurement unit according to the first rotation matrix; A two-dimensional information acquisition module, used for acquiring first two-dimensional information obtained by the camera device photographing the calibration plate on the projection plane and second two-dimensional information obtained by the projection camera photographing the calibration plate when the projection device to be calibrated rotates to a plurality of preset angles for projection as the turntable rotates; wherein the first two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the camera device coordinate system, and the second two-dimensional information is the two-dimensional information of each feature point of the calibration plate in the projection camera coordinate system; A first normal vector acquisition module, used to obtain first three-dimensional information of each feature point in the camera device coordinate system according to the two-dimensional information of each feature point in the camera device coordinate system; and obtain a projection plane normal vector in the camera device coordinate system according to the first three-dimensional information; A second rotation matrix acquisition module, used to obtain a second rotation matrix of the camera device coordinate system and the projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information; A second normal vector acquisition module, used to obtain the projection plane normal vector in the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix; The external parameter data acquisition module is used to obtain the external parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system.

10. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the steps of the method according to any one of claims 1 to 8 when executing the computer program.

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