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

Abstract

The application provides a method and device for obtaining calibration parameters of a projection device and a computer device. The method comprises the following steps: obtaining a unit rotation matrix of an inertial measurement unit, first two-dimensional information and second two-dimensional information obtained by a camera device and a projection camera when the camera device and the projection camera shoot a calibration board during projection of a to-be-calibrated projection device at a plurality of angles in a preset direction of a turntable; obtaining corresponding first three-dimensional information according to the first two-dimensional information; obtaining a second rotation matrix of a camera device coordinate system and a projection camera coordinate system according to the first three-dimensional information and the second two-dimensional information; obtaining a projection plane normal vector in the projection camera coordinate system according to a projection plane normal vector in the camera device coordinate system and the second rotation matrix; and obtaining external parameter data of a projection camera and the inertial measurement unit of the to-be-calibrated projection device according to the projection plane normal vector of the turntable coordinate system, the unit rotation matrix, a projection plane normal vector in the inertial measurement unit coordinate system and a projection plane normal vector in the projection camera coordinate system.

Description

TECHNICAL FIELD

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

[0002] In order to improve the stability of the projection picture of the projection device, the projection device is provided with functions such as trapezoidal correction and automatic obstacle avoidance, which are realized by an inertial measurement unit and a projection camera carried by the projection device. The accuracy of the functions such as trapezoidal correction and automatic obstacle avoidance is affected by the parameter calibration of the inertial measurement unit and the projection camera, and the related art has the technical defect that the parameters of the inertial measurement unit and the projection camera of the projection device cannot be accurately calibrated. SUMMARY

[0003] The present application aims to overcome the shortcomings and deficiencies in the prior art, and provides a method and device for acquiring calibration parameters of a projection device, and a computer device, which can accurately acquire the extrinsic parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated.

[0004] A first aspect of the embodiments of the present application provides a method for acquiring calibration parameters of a projection device, applied to a calibration system, the calibration system comprising 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; and the method comprises:

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

[0006] acquiring first two-dimensional information obtained by the camera device when the projection device to be calibrated projects while the turntable turns to a plurality of preset angles, and second two-dimensional information obtained by the projection camera when the projection camera captures a calibration board on the projection plane; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration board in a camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in a 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; and 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] obtaining extrinsic parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device 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, including:

[0011] constructing a first target function with the extrinsic 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 inputs and the projection plane normal vector in an actual projection camera coordinate system of the to-be-calibrated projection device as output;

[0012] constructing the second target 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 an included 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;

[0013] obtaining the extrinsic parameter data of the projection camera and the inertial measurement unit according to the second target function.

[0014] A second aspect of the embodiment of the application provides a calibration parameter acquisition device of a projection device, applied to a calibration system, the calibration system including a to-be-calibrated projection device, a turntable and a camera device; the to-be-calibrated projection device is arranged on the turntable; the to-be-calibrated projection device includes a projection camera and an inertial measurement unit;

[0015] The device includes:

[0016] a first rotation matrix acquisition module, configured to acquire a first rotation matrix of the turntable from facing a 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;

[0017] a two-dimensional information acquisition module, configured to acquire first two-dimensional information obtained by the camera device when the to-be-calibrated projection device projects a calibration board on the projection plane while the turntable turns to a plurality of preset angles and second two-dimensional information obtained by the projection camera when the projection camera projects the calibration board; the first two-dimensional information is two-dimensional information of each feature point of the calibration board in a camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in a projection camera coordinate system;

[0018] The first normal vector obtaining module is configured to obtain first three-dimensional information of each feature point in the camera device coordinate system according to 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.

[0019] The second rotation matrix obtaining module is configured 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.

[0020] The second normal vector obtaining module is configured to obtain a 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.

[0021] The extrinsic parameter data obtaining module is configured to obtain extrinsic parameter data of a projection camera and an inertial measurement unit of the projection device to be calibrated according to the projection plane normal vector in the turret 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, and the extrinsic parameter data comprises:

[0022] The first target function is constructed with the extrinsic parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system as input, and the projection plane normal vector in an actual projection camera coordinate system of the projection device to be calibrated as output.

[0023] The second target function is constructed 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 an included 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.

[0024] The extrinsic parameter data of the projection camera and the inertial measurement unit is obtained according to the second target function.

[0025] A third aspect of the embodiment of the application provides a computer device, which comprises a storage, a processor and a computer program stored in the storage and executable by the processor, and the processor implements steps of the projection device parameter calibration method when executing the computer program.

[0026] The calibration system applied by the application comprises a projection device to be calibrated, a turntable and a camera device, the projection device to be calibrated is arranged on the turntable. When the projection device to be calibrated projects at a plurality of preset angles with the turntable, the first two-dimensional information obtained by the camera device shooting the calibration board on the projection plane and the second two-dimensional information obtained by the projection camera shooting the calibration board are acquired, 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 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, 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 extrinsic parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated is 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 realizing the technical effect of accurately obtaining the extrinsic parameter data of the projection camera and the inertial measurement unit of the projection device to be calibrated.

[0027] In order to make the application clearer, the specific embodiments of the application will be described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The flow chart of the calibration parameter acquisition method of the projection device of one embodiment of the application.

[0029] Figure 2 The parameter relationship diagram of the calibration parameter acquisition method of the projection device of one embodiment of the application.

[0030] Figure 3 The module connection diagram of the calibration parameter acquisition device of the projection device of one embodiment of the application.

[0031] 100, calibration parameter acquisition device of projection device; 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, extrinsic parameter data acquisition module. DETAILED DESCRIPTION

[0032] In order to make the application clearer, the specific embodiments of the application will be described below with reference to the accompanying drawings.

[0033] It should be noted that the described embodiments are merely some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0034] In the following description, same numbers in different drawings represent same or similar elements unless otherwise indicated. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are merely used to distinguish similar objects, and do not necessarily describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. The specific meanings of the above terms in the present application can be understood by those of ordinary skill in the art according to specific circumstances. The singular forms "a", "an" and "the" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. The word "if" used herein can be interpreted as "when" or "when" or "in response to determining".

[0035] In addition, in the description of the present application, "multiple" means two or more, unless otherwise specified. The association between the associated objects described by "and / or" indicates that there can be three relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. The character " / " generally represents a "or" relationship between the associated objects before and after it.

[0036] The present application is applied to a calibration system, which includes a to-be-calibrated projection device, a turntable and a camera device. The to-be-calibrated projection device is arranged on the turntable. The to-be-calibrated projection device includes a projection camera and an inertial measurement unit.

[0037] The to-be-calibrated projection device is a device that forms a projection picture by emitting light rays. The to-be-calibrated projection device includes a projection light machine, a projection camera and an inertial measurement unit. The normal vector of the projection plane in the inertial measurement unit coordinate system is (1, 0, 0), and the extrinsic parameter data of the projection camera and the inertial measurement unit are to-be-calibrated data. In order to accurately obtain the to-be-calibrated data, the present application uses a projection plane as a reference surface, which can be a wall or a curtain. Specifically, a calibration board is laid on the projection plane to calibrate the extrinsic parameter data of the projection camera and the inertial measurement unit by means of the feature points of the calibration board and the projection picture of the to-be-calibrated projection device. The calibration board is a geometric model with a fixed-pitch pattern array, which is commonly used to determine the mutual relationship between the three-dimensional geometric position of a point on the surface of a spatial object and its corresponding point in an image.

[0038] The turntable is a rotatable carrier that can only rotate and cannot translate. The turntable is used to carry the to-be-calibrated projection device. Since the to-be-calibrated projection device is arranged on the turntable, the to-be-calibrated projection device rotates with the rotation of the turntable, which causes the to-be-calibrated projection device to change the angle relative to the projection plane. The state of the turntable when the to-be-calibrated projection device faces the preset projection plane is determined as the zero position state. The turntable coordinate system corresponding to the zero position state is consistent with the unit coordinate system of the inertial measurement unit. The rotation matrix corresponding to the turntable when rotating is the same as the rotation matrix of the inertial measurement unit. At this time, the normal vector of the projection plane in the turntable coordinate system corresponding to the zero position state is (1, 0, 0), and the normal vector of the projection plane in the inertial measurement unit coordinate system is also (1, 0, 0).

[0039] The camera device is a shooting device arranged outside the to-be-calibrated projection device. The projection image of the to-be-calibrated projection device and the image of the calibration board obtained by the camera device are used to obtain the extrinsic parameter data of the projection camera and the inertial measurement unit. The camera device and the projection device are located in the same vertical plane parallel to the projection plane, which can reduce the influence of spatial position synchronization on the calibration result.

[0040] Please refer to Figure 1 which is a calibration parameter acquisition method of the projection device according to an embodiment of the present application, comprising:

[0041] S1: obtaining a first rotation matrix of the turntable rotating from facing the projection plane to a plurality of preset angles; and obtaining a unit rotation matrix of the inertial measurement unit according to the first rotation matrix.

[0042] 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. The plurality of angles means that the turntable is rotated in a plurality of directions from the zero position state of facing the projection plane, and the angles of rotation in each direction are the same. For example, the turntable is controlled to rotate to the right by 15 degrees, to the upper right by 15 degrees, to the upper by 15 degrees, to the upper left by 15 degrees, and to the left by 15 degrees, etc. Each rotation angle can be regarded as a point position state of the turntable. The projection image of the projection device on the calibration board in different point position states is different.

[0043] S2: obtaining first two-dimensional information of the calibration board obtained by the camera device when the to-be-calibrated projection device projects on the calibration board on the projection plane, and second two-dimensional information of the calibration board obtained by the projection camera; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration board in the camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in the projection camera coordinate system.

[0044] Since the camera device coordinate system and the projection camera coordinate system are different, the first two-dimensional information and the second two-dimensional information corresponding to the same feature point on the calibration board are also different.

[0045] S3: Obtain first three-dimensional information of each feature point in the camera device coordinate system according to 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.

[0046] The plane fitting of the first three-dimensional information can obtain a plane equation corresponding to the projection plane normal vector in the camera device coordinate system, and the plane equation is as follows:

[0047]

[0048] Wherein, A, B and C are the projection plane normal vector in the camera device coordinate system, and x, y and z are the first three-dimensional information corresponding to the feature points.

[0049] 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.

[0050] The camera calibration can be performed according to the first three-dimensional information and the second two-dimensional information by using the calibrateCamera function of opencv, so as to obtain the intrinsic parameter of the projection camera and the extrinsic parameter data of the camera device and the projection camera. The extrinsic parameter data of 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. The opencv is an open source cross-platform computer vision and machine learning software library, and the calibrateCamera function can solve the intrinsic parameter of the camera and the extrinsic parameter of each view angle through the 2D / 3D correspondence of multiple views.

[0051] S5: Obtain a 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.

[0052] S6: Obtain the extrinsic parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device according to the projection plane normal vector in the turret 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.

[0053] ​Compared with the related art, the calibration system applied in the application comprises a to-be-calibrated projection device, a turntable and a camera device, and the to-be-calibrated projection device is arranged on the turntable. When the to-be-calibrated projection device projects at a plurality of preset angles with the turntable, first two-dimensional information obtained by the camera device when shooting a calibration board on a projection plane and second two-dimensional information obtained by a projection camera when shooting the calibration board are acquired, then 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 acquired according to the first two-dimensional information, so that the second rotation matrix of the camera device coordinate system and the projection camera coordinate system is acquired by using the first three-dimensional information and the second two-dimensional information, 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 extrinsic parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device is 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, so that the technical effect of accurately acquiring the extrinsic parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device is realized.

[0054] In a feasible embodiment, the step S2 of acquiring the first two-dimensional information obtained by the camera device when shooting the calibration board on the projection plane when the to-be-calibrated projection device projects at a plurality of preset angles with the turntable comprises the following steps.

[0055] S201: Acquire a first calibration board shooting image obtained by the camera device when shooting the calibration board laid on the projection plane.

[0056] S202: Perform feature point detection on the first calibration board shooting image to obtain third two-dimensional information of the feature points of the calibration board in the camera device coordinate system; wherein the third two-dimensional information corresponds to.

[0057] S203: Acquire a first projection shooting image obtained by the camera device when shooting the to-be-calibrated projection device projecting at a plurality of preset angles with the turntable.

[0058] S204: Identify the picture range of the projection picture in the first projection shooting image, and determine the third two-dimensional information located in the picture range as the first two-dimensional information.

[0059] In the embodiment, the first two-dimensional information used for calculating the projection plane normal vector in the camera device coordinate system can be acquired according to the picture range of the projection picture in the first projection shooting image.

[0060] In a feasible embodiment, the step S3 of obtaining the 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 the following steps.

[0061] According to the first two-dimensional information and the three-dimensional information of the feature points on the calibration board corresponding to the first two-dimensional information, the first three-dimensional information of each feature point in the camera device coordinate system is obtained.

[0062] The three-dimensional information of the feature points on the calibration board is known information, and the PnP algorithm of opencv can be used to calculate the first three-dimensional information of each feature point in the camera device coordinate system according to the first two-dimensional information and the three-dimensional information of the feature points on the calibration board corresponding to the first two-dimensional information. The full name of PnP algorithm is Perspective-n-Point, which is a method for solving the correspondence of 3D to 2D points.

[0063] In this embodiment, the first three-dimensional information corresponding to the first two-dimensional information can be calculated according to the first two-dimensional information and the three-dimensional information of the feature points on the calibration board corresponding to the first two-dimensional information, so that the first three-dimensional information of each feature point in the camera device coordinate system is accurately obtained.

[0064] In a feasible embodiment, the step S2 of obtaining the second two-dimensional information obtained by the projection camera when shooting the calibration board during the projection of the to-be-calibrated projection device at the preset multiple angles of the turntable, comprises:

[0065] S211: Obtain the second calibration board shooting image obtained by the projection camera when shooting the calibration board laid on the projection plane.

[0066] S212: Perform feature point detection on the second calibration board shooting image to obtain the fourth two-dimensional information of the feature points of the calibration board in the projection camera coordinate system.

[0067] S213: Obtain the second projection shooting image obtained by the projection camera when shooting the to-be-calibrated projection device at the preset multiple angles of the turntable.

[0068] S214: Identify the screen range of the projection screen in the second projection shooting image, and determine the fourth two-dimensional information located in the screen range as the second two-dimensional information.

[0069] In this embodiment, the second two-dimensional information used to calculate the second rotation matrix of the camera device coordinate system and the projection camera coordinate system can be obtained according to the screen range of the projection screen in the second projection shooting image.

[0070] In a feasible embodiment, the step S5 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:

[0071] The second rotation matrix and the projection plane normal vector in the camera device coordinate system are multiplied by a matrix to obtain the projection plane normal vector in the projection camera coordinate system.

[0072] The projection plane normal vector in the projection camera coordinate system is calculated as shown in the following formula:

[0073] n_cam = R_cam_fixed * n_fixed;

[0074] Wherein, 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.

[0075] Please refer to 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 by the second rotation matrix, so that the projection plane normal vector in the projection camera coordinate system can be calculated 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.

[0076] In one possible embodiment, the step S6 of obtaining the extrinsic data of the projection camera and the inertial measurement unit according to the projection plane normal vector in the turret 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:

[0077] S61: taking the extrinsic 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 inputs, and taking the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated as output, constructing a first target function.

[0078] Wherein, the step S61 comprises: multiplying the extrinsic data, the first rotation matrix and the projection plane normal vector in the inertial measurement unit coordinate system by a matrix, taking the projection plane normal vector in the actual projection camera coordinate system as the product of the matrix multiplication, and obtaining the first target function.

[0079] That is, the first target function is shown in the following formula:

[0080]

[0081] Wherein, is the projection plane normal vector in the actual projection camera coordinate system of the projection device to be calibrated, is the extrinsic data of the projection camera and the inertial measurement unit, is the first rotation matrix, ​A projection plane normal vector in the IMU coordinate system.

[0082] S62: Construct a second target 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 included 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.

[0083] The second target function is as follows:

[0084] ;

[0085] In the above formula, the and are unit vectors, is the included 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. When the included angle in the second target function is closer to 0, the extrinsic parameter data of the projection camera and the IMU is the most accurate.

[0086] S63: Obtain the extrinsic parameter data of the projection camera and the IMU according to the second target function.

[0087] In this embodiment, according to the second target function, 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, the extrinsic parameter data of the projection camera and the IMU is obtained, thereby obtaining the extrinsic parameter data of the projection camera and the IMU with the highest accuracy.

[0088] 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, which can be an image of a calibration board. The fixed-pitch pattern array of the calibration image can be different from the fixed-pitch pattern array of the calibration board laid on the projection plane.

[0089] The method for obtaining the calibration parameters of the projection device further includes:

[0090] S71: Obtain 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 board.

[0091] S72: Obtain the intrinsic parameter data of the projection camera, the intrinsic parameter data of the projection light machine, and the extrinsic parameter data of the projection camera and the projection light machine according to the second two-dimensional information, the two-dimensional feature point information, and the three-dimensional feature point information.

[0092] ;

[0093] wherein, is the intrinsic data of the projection camera, is the intrinsic data of the projection light machine, is the extrinsic data of the projection camera and the projection light machine, is the three-dimensional corner point data of the jthcorner point of the projection picture of the ithpreset angle, is the second two-dimensional coordinate point data, is the two-dimensional corner point data.

[0094] In the embodiment, the intrinsic data of the projection camera, the intrinsic data of the projection light machine, and the extrinsic data of the projection camera and the projection light machine can also be obtained through steps S71-S72 to obtain more projection device calibration parameters.

[0095] Referring to Figure 3 , the second embodiment of the present application provides a projection device calibration parameter acquisition device 100 applied to a calibration system, the calibration system comprising 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;

[0096] The device comprises:

[0097] A first rotation matrix acquisition module 101 is configured to obtain a first rotation matrix of the turntable rotating 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;

[0098] A two-dimensional information acquisition module 102 is configured to obtain first two-dimensional information obtained by the camera device shooting a calibration board on the projection plane when the projection device to be calibrated projects while the turntable rotates to a plurality of preset angles, and second two-dimensional information obtained by the projection camera shooting the calibration board; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration board in the camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in the projection camera coordinate system;

[0099] A first normal vector acquisition module 103 is configured 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;

[0100] A second rotation matrix acquisition module 104 is configured 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;

[0101] The second normal vector obtaining module 105 is configured to obtain 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.

[0102] The external parameter data obtaining module 106 is configured to obtain external parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device 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.

[0103] It should be noted that the projection device calibration parameter obtaining apparatus 100 provided by the second embodiment of the present application is only used as an example to illustrate the division of the above functional modules when the projection device calibration parameter obtaining method is executed, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the above-described functions. In addition, the projection device calibration parameter obtaining apparatus 100 provided by the second embodiment of the present application and the projection device calibration parameter obtaining method of the first embodiment of the present application belong to the same concept, and the implementation process is detailed in the method embodiment. Here, it is not repeated.

[0104] The third aspect of the embodiment of the present application provides a computer device, including a storage, a processor, and a computer program stored in the storage and executable by the processor, and the processor implements the steps of the projection device calibration parameter obtaining method as above when executing the computer program.

[0105] The device embodiments described above are only schematic, and the components illustrated as separate components can or can not be physically separate, and the components illustrated as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present application. Those skilled in the art can understand and implement without creative labor.

[0106] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media containing computer usable program code (including but not limited to disk storage, CD-ROM, optical storage, etc.).

[0107] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks or in conjunction with the flowcharts described above. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof.

[0108] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks or in conjunction with the flowcharts described above. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof. Figure 1 The flowchart and / or block diagram in the flowcharts can also be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s) or block diagram block(s) or combinations thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block(s) or block diagram block(s) or combinations thereof.

[0109] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0110] The memory can include non-persistent memory, Random Access Memory (RAM), and / or non-volatile memory, etc. in the form of a computer-readable medium, such as read only memory (ROM) or flash memory. The memory is an example of computer-readable media.

[0111] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can implement information storage by any method or technology. The 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 technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0112] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or apparatus that comprises a list of elements does not only include those elements, but can also include other elements not expressly listed or inherent to such process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0113] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for obtaining calibration parameters of a projection device, characterized in that, The application is applied to a calibration system, the calibration system comprises a to-be-calibrated projection device, a turntable and a camera device; the to-be-calibrated projection device is arranged on the turntable; The to-be-calibrated projection device comprises a projection camera and an inertial measurement unit; the method comprises: Obtaining a first rotation matrix of the turntable from facing a projection plane to a plurality of preset angles; obtaining a unit rotation matrix of the inertial measurement unit according to the first rotation matrix; Obtaining first two-dimensional information obtained by the camera device when the to-be-calibrated projection device projects while the turntable rotates to a plurality of preset angles, and second two-dimensional information obtained by the projection camera when the projection camera shoots a calibration board on the projection plane; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration board in a camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in a 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; and 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 the projection camera coordinate system according to the projection plane normal vector in the camera device coordinate system and the second rotation matrix; Obtaining external parameter data of the projection camera and the inertial measurement unit of the to-be-calibrated projection device according to the projection plane normal vector in the turntable coordinate system, the unit rotation matrix, a projection plane normal vector in the inertial measurement unit coordinate system and the projection plane normal vector in the projection camera coordinate system, comprising: Constructing a first target function with the external parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system as inputs, and a projection plane normal vector in an actual projection camera coordinate system of the to-be-calibrated projection device as output; Constructing a second target 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 an included 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; Obtaining the external parameter data of the projection camera and the inertial measurement unit according to the second target function.

2. The method of claim 1, wherein, The step of constructing the first target function with the to-be-obtained external parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system as inputs, and the projection plane normal vector in the actual projection camera coordinate system of the to-be-calibrated projection device as output, comprises: Multiplying the external parameter data, the first rotation matrix and the projection plane normal vector in the inertial measurement unit coordinate system by matrix, taking the projection plane normal vector in the actual projection camera coordinate system as a product of the matrix multiplication, and obtaining the first target function.

3. The method of claim 1, wherein, The step of 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 comprises: The second rotation matrix and the projection plane normal vector in the camera device coordinate system are multiplied to obtain the projection plane normal vector in the projection camera coordinate system.

4. The method of claim 1, wherein, The step of obtaining the first two-dimensional information obtained by the camera device when the to-be-calibrated projection device projects at a plurality of angles of the turntable comprises: Obtaining a first calibration board photographing image obtained by the camera device when the camera device photographs the calibration board laid on the projection plane; Obtaining the third two-dimensional information of the feature points of the calibration board in the camera device coordinate system by performing feature point detection on the first calibration board photographing image; Obtaining a first projection photographing image obtained by the camera device when the to-be-calibrated projection device projects at a plurality of angles of the turntable; 5. The method of claim 1, wherein, Identifying a picture range of the projection picture in the first projection photographing image, and determining the third two-dimensional information located in the picture range as the first two-dimensional information. The step of obtaining the 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:

6. The method of claim 1, wherein, Obtaining the first three-dimensional information of each feature point in the camera device coordinate system 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 board. The step of obtaining the second two-dimensional information obtained by the projection camera when the to-be-calibrated projection device projects at a plurality of angles of the turntable comprises: Obtaining a second calibration board photographing image obtained by the projection camera when the projection camera photographs the calibration board laid on the projection plane; Obtaining the fourth two-dimensional information of the feature points of the calibration board in the projection camera coordinate system by performing feature point detection on the second calibration board photographing image; Obtaining a second projection photographing image obtained by the projection camera when the to-be-calibrated projection device projects at a plurality of angles of the turntable; 7. The method of claim 1, wherein, Identifying a picture range of the projection picture in the second projection photographing image, and determining the fourth two-dimensional information located in the picture range as the second two-dimensional information. The to-be-calibrated projection device comprises a projection light machine, and a projection picture of the projection light machine is a calibration image. The method further comprises the following steps: Obtaining two-dimensional feature point information of the feature points of the calibration image and three-dimensional information of the feature points of the calibration image on the calibration board; 8. A device for acquiring calibration parameters of a projection device, characterized in that, Obtaining intrinsic parameter data of the projection camera, intrinsic parameter data of the projection light machine, and extrinsic parameter data of the projection camera and the projection light machine according to the second two-dimensional information, the two-dimensional feature point information, and the three-dimensional information of the feature points. The apparatus is applied to a calibration system, the calibration system comprising a to-be-calibrated projection device, a turntable, and a camera device; the to-be-calibrated projection device is arranged on the turntable; the to-be-calibrated projection device comprises a projection camera and an inertial measurement unit. The apparatus comprises: The first rotation matrix obtaining module is configured to obtain a first rotation matrix of the rotating platform from facing a projection plane to a preset angle; and obtain a unit rotation matrix of an inertial measurement unit according to the first rotation matrix; The two-dimensional information obtaining module is configured to obtain first two-dimensional information obtained by a camera device shooting a calibration board on the projection plane and second two-dimensional information obtained by the projection camera shooting the calibration board when the projection device to be calibrated projects while the rotating platform rotates to a preset angle; wherein the first two-dimensional information is two-dimensional information of each feature point of the calibration board in a camera device coordinate system, and the second two-dimensional information is two-dimensional information of each feature point of the calibration board in a projection camera coordinate system; The first normal vector obtaining module is configured 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; The second rotation matrix obtaining module is configured 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; The second normal vector obtaining module is configured to obtain a 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 extrinsic parameter data obtaining module is configured to obtain extrinsic parameter data of a projection camera and an inertial measurement unit of the projection device to be calibrated according to the projection plane normal vector in the rotating platform coordinate system, the unit rotation matrix, a projection plane normal vector in an inertial measurement unit coordinate system, and the projection plane normal vector in the projection camera coordinate system, including: a first target function is constructed with the extrinsic parameter data of the projection camera and the inertial measurement unit, the first rotation matrix, the projection plane normal vector in the inertial measurement unit coordinate system as inputs, and a projection plane normal vector in an actual projection camera coordinate system of the projection device to be calibrated as output; a second target function is constructed 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 an included 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; the extrinsic parameter data of the projection camera and the inertial measurement unit is obtained according to the second target function.

9. A computer device, comprising: The computer program product comprises a storage, a processor, and a computer program stored in the storage and executable by the processor, and the processor implements the steps of the method according to any one of claims 1 to 7 when executing the computer program.

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