Calibration method and device of projection equipment, electronic equipment and storage medium

Abstract

The invention discloses a calibration method and device of projection equipment, electronic equipment and a storage medium, and relates to the technical field of projection. The method comprises the following steps: shooting a calibration plate through a target camera of target projection equipment to obtain a first calibration image; preset calibration parameters of preset projection equipment of the same equipment type are obtained and serve as initial calibration parameters of target projection equipment, and the initial calibration parameters are obtained by calibrating the preset projection equipment based on multiple second calibration images in advance; according to the initial calibration parameter, the first calibration image and the calibration plate parameter, obtaining a re-projection error value of at least one angular point in the first calibration image as a first error value; and performing iterative optimization on the parameter value of the initial calibration parameter by using a preset optimization algorithm according to the first error value to obtain a target calibration parameter of the target projection equipment. In this way, more accurate target calibration parameters of the target projection equipment can be obtained more quickly.

Description

Technical Field

[0001] The present application relates to the field of projection technology, and in particular to a calibration method, device, electronic device and storage medium for a projection device. Background Art

[0002] Projection equipment generally includes components such as cameras and optical machines. The optical machine is used to project image information, and the camera is used to assist in completing the focusing, side projection and other functions of the optical machine. The combination of the camera and the optical machine can be regarded as a binocular system.

[0003] However, the binocular system generally needs to be calibrated before use, and the calibration of the binocular system in the related art requires collecting images of the calibration plate in various postures, and the calibration efficiency is low, which greatly reduces the production efficiency of the projection equipment on the production line of the projection equipment. Summary of the invention

[0004] The present application proposes a method, an apparatus, an electronic device and a storage medium for calibrating a projection device, so as to improve the accuracy of the calibration of the projection device.

[0005] In a first aspect, an embodiment of the present application provides a calibration method for a projection device, the projection device including a camera and an optical machine, the method including: photographing a calibration plate with a target camera of a target projection device to obtain a first calibration image, the calibration plate being provided with a calibration pattern; obtaining preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device, the preset projection device being of the same device type as the target projection device, the preset calibration parameters being obtained by calibrating the preset projection device in advance based on a plurality of second calibration images, the plurality of second calibration images being obtained by photographing calibration plates of various postures with a preset camera of the preset projection device; obtaining a reprojection error value of at least one corner point in the first calibration image as a first error value according to the initial calibration parameters, the first calibration image and the calibration plate parameters; and iteratively optimizing the parameter values ​​of the initial calibration parameters using a preset optimization algorithm and according to the first error value to obtain the optimized initial calibration parameters as target calibration parameters of the target projection device.

[0006] In a second aspect, an embodiment of the present application provides a calibration device for a projection device, wherein the projection device includes a camera and an optical machine, and the device includes: an image capturing module, configured to capture a calibration plate through a target camera of a target projection device to obtain a first calibration image, wherein a calibration pattern is provided on the calibration plate; an initial parameter acquisition module, configured to capture preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device, wherein the preset projection device is of the same device type as the target projection device, and the preset calibration parameters are obtained by calibrating the preset projection device based on a plurality of second calibration images in advance, wherein the plurality of second calibration images are captured by a preset camera of the preset projection device for calibration plates of various postures; an error value acquisition module, configured to capture a reprojection error value of at least one corner point in the first calibration image as a first error value based on the initial calibration parameters, the first calibration image, and calibration plate parameters; and an iterative optimization module, configured to iteratively optimize the parameter values ​​of the initial calibration parameters using a preset optimization algorithm and based on the first error value, to obtain the optimized initial calibration parameters as target calibration parameters of the target projection device.

[0007] In a third aspect, an embodiment of the present application provides an electronic device, comprising: one or more processors; a memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to execute the above-mentioned method.

[0008] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a program code is stored. The program code can be called by a processor to execute the above method.

[0009] In the solution provided by the present application, a first calibration image is obtained by photographing a calibration plate with a target camera of a target projection device, a calibration pattern is provided on the calibration plate, and the target projection device also includes a target optical machine; preset calibration parameters of a preset projection device are obtained as initial calibration parameters of the target projection device, the preset projection device and the target projection device are of the same device type, the preset calibration parameters are obtained by calibrating the preset projection device in advance based on a plurality of second calibration images, and the plurality of second calibration images are obtained by photographing calibration plates of various postures with a preset camera of the preset projection device; according to the preset calibration parameters, the first calibration image and the calibration plate parameters, a reprojection error value of at least one corner point in the first calibration image is obtained as a first error value; using a preset optimization algorithm and according to the first error value, the parameter values ​​of the initial calibration parameters are iteratively optimized to obtain the optimized initial calibration parameters as the target calibration parameters of the target projection device. In this way, when calibrating the parameters of the target projection device, the calibration parameters obtained by accurately calibrating the preset projection device of the same device type as the target projection device are used as the initial calibration parameters of the target projection device; then, the preset optimization algorithm is used, and the reprojection error value of the corner point is combined to iteratively optimize the initial calibration parameters, which can improve the convergence speed and optimization accuracy of the preset optimization algorithm, thereby obtaining more accurate target calibration parameters of the target projection device more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A schematic flow chart of a method for calibrating a projection device provided in an embodiment of the present application is shown.

[0012] Figure 2 A schematic diagram of a calibration scene of a calibration method for a projection device provided in an embodiment of the present application is shown.

[0013] Figure 3 A schematic flow chart of a method for calibrating a projection device provided in another embodiment of the present application is shown.

[0014] Figure 4 A schematic diagram of a calibration scene of a calibration method for a projection device provided in another embodiment of the present application is shown.

[0015] Figure 5 A schematic diagram of coordinate system transformation of a calibration method for a projection device provided in an embodiment of the present application is shown.

[0016] Figure 6 Shows Figure 4 A flowchart of the sub-steps of step S290 in one implementation manner.

[0017] Figure 7 It is a block diagram of a calibration device for a projection device provided according to an embodiment of the present application.

[0018] Figure 8 It is a block diagram of an electronic device for executing a calibration method for a projection device according to an embodiment of the present application.

[0019] Fig. 9 It is a storage unit of an embodiment of the present application for storing or carrying a program code for implementing a calibration method for a projection device according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, 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 making creative work are within the scope of protection of this application.

[0021] It should be noted that in some processes described in the specification, claims and the above-mentioned drawings of the present application, multiple operations that appear in a specific order are included, and these operations may not be executed or executed in parallel in the order in which they appear in this article. The sequence numbers of operations such as S110, S120, etc. are only used to distinguish different operations, and the sequence numbers themselves do not represent any execution order. In addition, these processes may include more or less operations, and these operations may be executed in sequence or in parallel. And, the terms "first", "second", etc. in the specification, claims and the above-mentioned drawings of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or server that includes a series of steps or sub-modules is not necessarily limited to those steps or sub-modules explicitly listed, but may include other steps or sub-modules that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0022] The inventor proposes a method, device, electronic device and storage medium for calibrating a projection device. The calibration method for a projection device provided in an embodiment of the present application is described in detail below.

[0023] Please refer to Figure 1 , Figure 1 A flowchart of a method for calibrating a projection device provided in an embodiment of the present application is shown below. Figure 1 The calibration method of the projection device provided in the embodiment of the present application is described in detail. The calibration method of the projection device may include the following steps:

[0024] Step S110: photographing a calibration plate with a target camera of a target projection device to obtain a first calibration image, wherein a calibration pattern is arranged on the calibration plate.

[0025] In this embodiment, if Figure 2 As shown, the target projection device includes a target camera and a target optical machine, and the calibration pattern on the calibration plate can be as follows Figure 2 The black and white checkerboard pattern shown may, of course, be other types of patterns, which are not limited in this embodiment.

[0026] Based on this, when calibrating the parameters of the target projection device, the target camera in the target projection device can first be used to shoot the calibration plate to obtain the corresponding first calibration image. Subsequently, image processing can be performed based on the first calibration image, and according to the image processing results, both the target camera and the target optical machine can be calibrated.

[0027] Step S120: Obtain preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device, the preset projection device and the target projection device are of the same device type, and the preset calibration parameters are obtained by calibrating the preset projection device in advance based on multiple second calibration images, and the multiple second calibration images are obtained by taking a preset camera of the preset projection device for calibration plates in multiple postures.

[0028] It can be understood that for projection devices of the same device type on the production line, even if there are differences in process manufacturing, the models and machine parameters of the optical machine and camera, as well as the relative positions of the optical machine and camera are very close; therefore, according to the device type of the target projection device, the preset calibration parameters corresponding to the device type can be obtained as the initial calibration parameters of the target projection device. Based on this, for each device type of projection device, this embodiment can pre-precisely calibrate the preset projection device of this device type, and the precise calibration method can be a traditional dual-target calibration method. Among them, the preset projection device also includes a preset optical machine and a preset camera. Based on this, the preset camera in the preset projection device can be used to shoot calibration plates in multiple postures to obtain multiple second calibration images in different postures; and based on the multiple second calibration images, the preset projection device is calibrated to obtain accurate preset calibration parameters for the preset projection device.

[0029] Furthermore, when calibrating the parameters of the target projection device, the precise preset calibration parameters of the preset projection device of the same device type as the target projection device can be used as the initial calibration parameters of the target projection device in advance. In this way, the initial calibration parameters of the target projection device can be better than the customized initial calibration parameters, that is, closer to the most realistic calibration parameters of the target projection device.

[0030] In other embodiments, for each type of projection device, multiple preset projection devices of the device type may be accurately calibrated in advance, so as to obtain accurate preset calibration parameters of each preset projection device; further, the average of multiple accurate preset calibration parameters may be obtained as the preset calibration parameters of the projection device of the device type. In this way, more precise and accurate initial calibration parameters may be obtained.

[0031] Step S130: acquiring a reprojection error value of at least one corner point in the first calibration image as a first error value according to the preset calibration parameters, the first calibration image and calibration plate parameters.

[0032] In this embodiment, the initial calibration parameters may include at least the intrinsic parameters of the preset camera, the distortion parameters of the preset camera, the intrinsic parameters of the preset optical machine, the distortion parameters of the preset optical machine, and the first extrinsic parameters between the preset camera and the preset optical machine. The calibration board parameters can be understood as the size information of the checkerboard on the calibration board. Figure 2Taking the calibration plate shown as an example, the calibration plate parameters may include the length information or width information of the checkerboard on the calibration plate. Based on this, when the calibration plate parameters are known values, the actual positions of the corner points in the first calibration image on the calibration plate are also known, and then based on the aforementioned initial calibration parameters and combined with the actual positions of one or more corner points on the calibration plate, one or more corner points can be mapped in the first calibration image, thereby obtaining the difference between the actual position and the mapped position of one or more corner points in the first calibration image as the aforementioned reprojection error value, that is, obtaining the first error value.

[0033] Step S140: using a preset optimization algorithm and according to the first error value, iteratively optimizing the parameter values ​​of the initial calibration parameters to obtain the optimized initial calibration parameters as target calibration parameters of the target projection device.

[0034] It can be understood that the smaller the first error value is, the more accurate the initial calibration parameters are. Therefore, after obtaining the first error value, the preset optimization algorithm can be used to iteratively optimize the parameter values ​​of the initial calibration parameters according to the first error value until the preset optimization conditions are met, thereby obtaining the optimized initial calibration parameters as the target calibration parameters of the target projection device. Among them, the preset optimization conditions at least include: the first error value is less than the first threshold value, the first error value no longer changes, and the number of iterative optimizations reaches at least one of the first number threshold values. The first threshold value and the first number threshold value are both values ​​that can be preset. The preset optimization algorithm can be the Levenberg-Marquardt method (Levenberg-Marquardt method, LM algorithm). Of course, other optimization algorithms that can be used to optimize the calibration parameters are also within the scope of protection of this application, and no examples are given here one by one.

[0035] In this embodiment, when calibrating the parameters of the target projection device, the calibration parameters obtained by accurately calibrating a preset projection device of the same device type as the target projection device are used as the initial calibration parameters of the target projection device; since the initial calibration parameters are relatively accurate parameter values, the preset optimization algorithm is used again, and the initial calibration parameters are iteratively optimized in combination with the reprojection error values ​​of the corner points, which can greatly improve the convergence speed and optimization accuracy of the preset optimization algorithm, thereby more quickly obtaining more accurate target calibration parameters of the target projection device.

[0036] Please refer to Figure 3 , Figure 3 A flowchart of a method for calibrating a projection device provided in an embodiment of the present application is shown below. Figure 3 The calibration method of the projection device provided in the embodiment of the present application is described in detail. The calibration method of the projection device may include the following steps:

[0037] Step S210: photographing the calibration plate through the preset camera of the preset projection device to obtain a third calibration image.

[0038] In this embodiment, the preset calibration parameters of the preset projection device may at least include: the internal parameters of the preset camera in the preset projection device, the distortion parameters of the preset camera, the internal parameters of the preset optical machine, the distortion parameters of the preset optical machine, and the first external parameters between the preset camera and the preset optical machine. Among them, the internal parameters may include the principal point and the focal length, the distortion parameters may include the radial distortion parameters, and the first external parameters may include the relative rotation parameters and the relative translation parameters. The aforementioned preset calibration parameters may be obtained by accurately calibrating the preset projection device using the precise calibration method mentioned in the aforementioned embodiment before step S210, and the detailed process of the precise calibration will not be repeated here.

[0039] In practical applications, such as Figure 4 As shown, generally, projection devices of the same device type are placed on a preset base, and the calibration pattern on the calibration plate is photographed to realize parameter calibration of each projection device. Based on this, the preset base itself can ensure the repeatability of different projection devices of the same device type at the same position within a certain range, and the installation accuracy of the projection device itself can also ensure the identity of the position of the camera and the optical machine relative to the projection device itself within a certain range. Therefore, when the projection device is placed on the preset base, the position of the optical machine and camera thereon is also fixed within a certain range relative to the preset base and the calibration plate outside the preset base. It can be understood that the preset calibration parameters, in addition to the aforementioned parameters, may also include: a second external parameter between the preset camera and the calibration plate, and a third external parameter between the preset optical machine and the calibration plate.

[0040] Furthermore, after the preset projection device is accurately calibrated, the preset projection device can be placed on a preset base to realize external parameter calibration; the external parameter calibration can be understood as obtaining the third external parameter between the preset optical machine and the calibration plate placed on the preset base, and the second external parameter between the preset camera and the calibration plate, with the help of the relative fixed position of the preset base and the calibration plate. It can also be understood as an initial calibration of the external parameters between the preset base and the calibration plate, thereby providing better external parameter initial values ​​for the subsequent calibration of other projection devices of the same device type.

[0041] Therefore, the third calibration image can be obtained by photographing the calibration plate through a preset camera of the preset projection device.

[0042] Step S220: Obtain an optical-mechanical reprojection error value of a corner point in the third calibration image as a second error value according to a first initial extrinsic parameter between the preset optical-mechanical machine and the calibration plate, the first extrinsic parameter, and the calibration plate parameter.

[0043] In this example, see Figure 5 , for ease of understanding, we will combine Figure 5 The coordinate system transformation diagram is shown in the figure. Figure 5 The first coordinate system is a three-dimensional coordinate system based on the calibration plate, the second coordinate system is a two-dimensional coordinate system based on the imaging plane of the optical machine, and the third coordinate system is a two-dimensional coordinate system based on the imaging plane of the camera.

[0044] Specifically, according to the calibration plate parameters, the first coordinate information of the corner point in the third calibration image in the first coordinate system is obtained; according to the first initial external parameter, the first external parameter, the internal parameter of the preset camera and the distortion parameter of the preset camera, the first coordinate information is converted into the third coordinate system to obtain the third coordinate information of the corner point in the third coordinate system, and the third coordinate system is a two-dimensional coordinate system established based on the imaging plane of the camera; according to the coordinate difference between the third coordinate information of the corner point in the third coordinate system and the preset coordinate information, the optical mechanical reprojection error value of the corner point in the third calibration image is determined as the second error value. Wherein, the preset coordinate information is the pixel coordinate information extracted from the corner point in the third calibration image.

[0045] It can be understood that obtaining the first coordinate information corresponding to the corner point in the third calibration plate image in the first coordinate system is actually to obtain the actual position information on the calibration plate corresponding to the corner point in the third calibration plate image. Therefore, it is necessary to use the calibration plate parameters, that is, the size information of the chessboard to provide actual scale information, such as length information and width information, to obtain the first coordinate information corresponding to the corner point in the third calibration image in the first coordinate system. Further, firstly, the first coordinate information can be converted into the optomechanical coordinate system according to the first initial external parameter to obtain the fourth coordinate information of the corner point in the optomechanical coordinate system, wherein the optomechanical coordinate system is a three-dimensional coordinate system established based on the optomechanical system, and the conversion between the coordinate information in the optomechanical coordinate system and the coordinate information in the aforementioned second coordinate system can be converted according to the intrinsic parameters and distortion parameters of the optomechanical system. Secondly, according to the first external parameter, the fourth coordinate information is converted into the camera coordinate system to obtain the fifth coordinate information of the corner point in the camera coordinate system, wherein the camera coordinate system is a three-dimensional coordinate system established based on the camera. Finally, according to the preset camera intrinsic parameters and the preset camera distortion parameters, the fifth coordinate information is converted to the third coordinate system to obtain the third coordinate information of the corner point in the third coordinate system. In this way, in the process of obtaining the optical-mechanical reprojection error value of the corner point, the optical-mechanical reprojection error value is converted to the imaging plane of the camera for calculation by means of the accurate relative posture relationship between the optical-mechanical machine and the camera, which can avoid calculating the reprojection error value in the respective imaging planes of the optical-mechanical machine and the camera, resulting in inaccurate parameter optimization and other problems.

[0046] Among them, the first initial external parameter can be obtained by using the PNP algorithm, firstly, the preset camera of the preset projection device shoots the feature map of the preset optical machine of the preset projection device transmitted to the calibration plate, and obtains the fourth calibration image, wherein the feature map can be a Gray code or a sinusoidal fringe map. And according to the three-dimensional coordinate information of multiple feature points in the first coordinate system, the three-dimensional coordinate information of multiple feature points in the second coordinate system, the internal parameters of the preset optical machine and the distortion parameters of the preset optical machine in the fourth calibration image, the first initial external parameter between the preset optical machine and the calibration plate is determined. The first initial external parameter can be understood as the relative posture relationship between the preset optical machine and the calibration plate, wherein the first initial external parameter can specifically include the first initial rotation parameter and the first initial translation parameter.

[0047] Exemplarily, the first initial external parameter can be expressed as (R l , t l ), R l is the first initial rotation parameter, t l is the first initial translation parameter, and the first external parameter can be expressed as (R, t ), where R is the first rotation parameter, t is the first translation parameter, and the preset coordinate information of the corner point in the third coordinate system is a known value, which can be identified as y 0 , the first coordinate information can be simply expressed as x, where x does not represent the horizontal axis coordinate value, but represents the three-dimensional coordinate information of the corner point in the first coordinate system corresponding to the calibration plate. Based on this, the second coordinate information can be expressed as y l =R l *x+t l , and with the help of the (R, t) obtained by precise calibration, the second coordinate information is converted to the third coordinate system to obtain the third coordinate information, which can be expressed as y = R*y l +t. Further, the second error value can be calculated using the following formula:

[0048]

[0049] Where n represents the total number of corner points in the third calibration image, s 1 The sum of the reprojection error values ​​of all corner points is represented as the second error value.

[0050] Step S230: Utilizing the preset optimization algorithm and according to the second error value, optimizing the first initial external parameter to obtain an optimized first initial external parameter as the third external parameter.

[0051] Among them, the preset optimization algorithm can still be the aforementioned LM algorithm. Specifically, the preset optimization algorithm is used to optimize the first initial extrinsic parameter until the second error value meets the preset optimization condition, and the optimized first initial extrinsic parameter is obtained as the third extrinsic parameter. Among them, the target optimization condition may include at least one of the following conditions: the second error value is less than the second threshold, the second error value no longer changes, and the number of iterative optimizations reaches the second numerical threshold. Among them, the second threshold and the second numerical threshold can both be pre-set values, and examples are not given here one by one. Taking the aforementioned example as an example, during the optimization process, the first external parameter (R, t) is fixed, and only the first initial external parameter (R l , t l ) is optimized to obtain the optimized first initial external parameter (R l , t l ) as the third external reference.

[0052] Step S240: acquiring a camera reprojection error value of a corner point of the third calibration image according to a second initial external parameter between the preset camera and the calibration plate and the calibration plate parameters as a third error value.

[0053] In this embodiment, Figure 5 , the process of obtaining the third error value is described. Similarly, firstly, based on the calibration plate parameters, the first coordinate information of the corner point in the third calibration image in the first coordinate system is obtained, that is, the actual position information in the calibration plate corresponding to the corner point in the third calibration image is obtained; according to the second initial external parameter, the internal parameter of the preset camera and the distortion parameter of the preset camera, the first coordinate information is converted to the third coordinate system to obtain the second coordinate information of the corner point in the third coordinate system; according to the coordinate difference between the second coordinate information of the corner point in the third coordinate system and the preset coordinate information, the camera reprojection error value of the corner point in the third calibration image is determined as the third error value. Similarly, the preset coordinate information is the pixel coordinate information extracted for the corner point in the third calibration image.

[0054] Among them, the method for obtaining the second initial external parameters is similar to the method for obtaining the aforementioned first initial external parameters, and both can also use the PNP algorithm, and determine the second initial external parameters between the preset camera and the calibration plate according to the three-dimensional coordinate information of the corner points in the third calibration image in the first coordinate system, the two-dimensional coordinate information of the corner points in the third coordinate system, the intrinsic parameters of the preset camera, and the distortion parameters of the preset camera.

[0055] Exemplarily, the first initial external parameter can be expressed as (R r , t r ), R r is the second initial rotation parameter, t ris the second initial translation parameter. The preset coordinate information of the corner point in the third coordinate system is a known value and can be identified as y 0 , the first coordinate information can be simply expressed as x, where x does not represent the horizontal axis coordinate value, but represents the three-dimensional coordinate information of the corner point in the first coordinate system corresponding to the calibration plate. Based on this, the second coordinate information can be expressed as y 2 =R r *x+t r Furthermore, the third error value can be calculated using the following formula:

[0056]

[0057] Where n represents the total number of corner points in the third calibration image, s 2 The sum of the reprojection error values ​​of all corner points is represented as the third error value.

[0058] Step S250: Utilizing the preset optimization algorithm and according to the third error value, optimizing the second initial extrinsic parameter to obtain an optimized second initial extrinsic parameter as the second extrinsic parameter.

[0059] In this embodiment, the optimization principle of step S250 is similar to the optimization principle in the aforementioned content, and reference may be made to the content in the aforementioned embodiment, which will not be repeated here.

[0060] Step S260: photographing a calibration plate with a target camera of a target projection device to obtain a first calibration image, wherein a calibration pattern is arranged on the calibration plate.

[0061] After completing the precise calibration of the preset projection device of the same device type as the target projection device and the external parameter calibration placed on the preset base, the parameter values ​​obtained by the aforementioned precise calibration and the external parameter values ​​obtained by the external parameter calibration can be stored. Furthermore, the target projection device to be calibrated of the same device type as the preset projection device can be placed on the preset base, and the parameter calibration can be performed in combination with the parameter values ​​obtained by the aforementioned precise calibration and the external parameter values ​​obtained by the external parameter calibration.

[0062] Step S270: obtaining preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device.

[0063] It can be understood that, since preset calibration parameters of preset projection devices of multiple device types may be pre-stored, that is, there are multiple preset calibration parameters, and the multiple preset calibration parameters correspond to the multiple device types one by one, the method for obtaining the preset calibration parameters corresponding to each device type can refer to the above content, and will not be repeated here. Therefore, before calibrating the target projection device, the preset calibration parameters corresponding to the device type are first obtained from the multiple preset calibration parameters as the optimal initial calibration parameters of the target projection device.

[0064] Step S280: acquiring a reprojection error value of at least one corner point in the first calibration image as a first error value according to the initial calibration parameters, the first calibration image, and calibration plate parameters.

[0065] In this embodiment, the target projection device, the first error value may include a first sub-error value and a second sub-error value. The first sub-error value may refer to the aforementioned method for obtaining the second error value to obtain the optical reprojection error value, and the second sub-error value may refer to the aforementioned method for obtaining the third error value to obtain the camera reprojection error value, which will not be described one by one here.

[0066] Step S290: using a preset optimization algorithm and according to the first error value, iteratively optimizing the parameter values ​​of the initial calibration parameters to obtain the optimized initial calibration parameters as target calibration parameters of the target projection device.

[0067] In some embodiments, the second extrinsic parameter includes a second rotation parameter and a second translation parameter, and the third extrinsic parameter includes a third rotation parameter and a third translation parameter. Figure 6 , step S290 may include the following contents from step S291 to step S293:

[0068] Step S291: Utilizing the preset optimization algorithm and based on the first sub-error value, the internal parameters of the preset optical machine, the distortion parameters of the preset optical machine, and the parameter values ​​of the third rotation parameters are iteratively optimized to obtain the internal parameters of the target optical machine, the distortion parameters of the target optical machine, and the rotation parameters of the target optical machine compared to the calibration plate.

[0069] Considering that the translation amount is generally only controlled by the structural accuracy, and the accuracy is relatively high, if the third translation parameter is optimized synchronously during the mass production calibration process, the final optimized numerical solution will be unstable. Therefore, only the preset optimization algorithm can be used to iteratively optimize the parameter values ​​of the preset optical machine's internal parameters, the preset optical machine's distortion parameters, and the third rotation parameters until the first sub-error value meets the first sub-optimization condition, so that the optimized internal parameters of the preset optical machine are used as the internal parameters of the target optical machine, the optimized distortion parameters of the preset optical machine are used as the distortion parameters of the target optical machine, and the optimized third rotation parameters are used as the rotation parameters of the target optical machine compared to the calibration plate. Among them, the first sub-optimization condition includes at least one of the following conditions: the first sub-error value is less than the third threshold, the first sub-error threshold no longer changes, and the number of iterative optimizations is greater than the third number threshold.

[0070] Step S292: Utilizing the preset optimization algorithm and based on the second sub-error value, the intrinsic parameters of the preset camera, the distortion parameters of the preset camera, and the parameter values ​​of the second rotation parameters are iteratively optimized to obtain the intrinsic parameters of the target camera, the distortion parameters of the target camera, and the rotation parameters of the target camera compared to the calibration plate.

[0071] Similarly, considering that the translation amount is generally only controlled by the structural accuracy, and the accuracy is relatively high, if the second translation parameter is optimized synchronously during the mass production calibration process, the final optimized numerical solution will be unstable. Therefore, only the preset optimization algorithm can be used to iteratively optimize the parameter values ​​of the preset optical machine's internal parameters, the preset optical machine's distortion parameters, and the second rotation parameters until the second sub-error value satisfies the second sub-optimization condition, thereby using the optimized internal parameters of the preset camera as the internal parameters of the target camera, the optimized distortion parameters of the preset camera as the distortion parameters of the target camera, and the optimized second rotation parameters as the rotation parameters of the target camera compared to the calibration plate. Among them, the second sub-optimization condition includes at least one of the following conditions: the second sub-error value is less than the fourth threshold, the second sub-error threshold no longer changes, and the number of iterative optimization times is greater than the fourth times threshold.

[0072] Step S293: Obtain the rotation parameters and translation parameters between the target optical machine and the target camera according to the rotation parameters of the target optical machine compared to the calibration plate, the rotation parameters of the target camera compared to the calibration plate, the second translation parameters and the third translation parameters.

[0073] Furthermore, after completing the extrinsic calibration between the target optical machine and the calibration plate, and completing the extrinsic calibration between the target camera and the calibration plate, the parameter values ​​obtained by the extrinsic calibration can be further used to calibrate the target optical machine and the target camera.

[0074] Specifically, the first rotation parameter can be optimized by the following formula:

[0075]

[0076] Among them, R represents the first rotation parameter, R l is the rotation parameter of the target optical machine compared to the calibration plate, R r is the rotation parameter of the target camera compared to the calibration plate.

[0077] The first translation parameter can be optimized by the following formula:

[0078] t=-R*t r +t l

[0079] Wherein, t represents the first rotation parameter, R represents the first rotation parameter, t l is the second translation parameter, t r is the third translation parameter.

[0080] In this embodiment, the preset projection device is accurately calibrated in advance with the help of traditional calibration technology to obtain the initial values ​​of internal parameters and initial values ​​of distortion of other projection devices of the same device type during calibration; then based on the accurately obtained initial values ​​of internal parameters and initial values ​​of distortion, and with the help of the installation accuracy of the preset base and projection device, more accurate initial values ​​of external parameters are provided for the calibration of other devices of the same type. Finally, with good initial values ​​of internal parameters, initial values ​​of distortion and initial values ​​of external parameters, the same type of target projection devices are calibrated, and the calibration can be completed with the help of at least one image. Moreover, since the initial calibration parameters are more accurate parameter values, the preset optimization algorithm is used again, and the initial calibration parameters are iteratively optimized in combination with the reprojection error value of the corner point, which can greatly improve the convergence speed and optimization accuracy of the preset optimization algorithm, thereby more quickly obtaining more accurate target calibration parameters of the target projection device, while ensuring the basic functions and accuracy of the projection device such as automatic focus and automatic side projection correction, and improving the production efficiency during mass production.

[0081] Please refer to Figure 7 , which shows a structural block diagram of a projection device calibration device 300 provided in an embodiment of the present application. The device 300 may include: an image capturing module 310, an initial parameter acquisition module 320, an error value acquisition module 330 and an iterative optimization module 340.

[0082] The image capturing module 310 is used to capture a calibration plate through a target camera of a target projection device to obtain a first calibration image, where a calibration pattern is arranged on the calibration plate.

[0083] The initial parameter acquisition module 320 is used to obtain preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device. The preset projection device is of the same device type as the target projection device. The preset calibration parameters are obtained by calibrating the preset projection device in advance based on multiple second calibration images. The multiple second calibration images are taken by a preset camera of the preset projection device for calibration plates in multiple postures.

[0084] The error value acquisition module 330 is used to acquire a reprojection error value of at least one corner point in the first calibration image as a first error value according to the initial calibration parameters, the first calibration image and calibration plate parameters.

[0085] The iterative optimization module 340 is used to iteratively optimize the parameter values ​​of the initial calibration parameters using a preset optimization algorithm and according to the first error value, so as to obtain the optimized initial calibration parameters as the target calibration parameters of the target projection device.

[0086] In some embodiments, the preset projection device includes a preset optical machine and a preset camera, the preset calibration parameters include a first external parameter between the preset camera and the preset optical machine, the preset projection device is placed on a preset base, and the preset calibration parameters also include a second external parameter between the preset camera and the calibration plate, and a third external parameter between the preset optical machine and the calibration plate. The calibration device 300 of the projection device may also include: a third calibration image acquisition module, a second error acquisition module, a third external parameter acquisition module, a third error acquisition module, and a second external parameter acquisition module. Among them, the third calibration image acquisition module can be used to photograph the calibration plate through the preset camera of the preset projection device to obtain a third calibration image; the second error acquisition module can be used to obtain the optical machine reprojection error value of the corner point in the third calibration image according to the first initial external parameter between the preset optical machine and the calibration plate, the first external parameter, and the calibration plate parameter, as the second error value. The third external parameter acquisition module can be used to optimize the first initial external parameter using the preset optimization algorithm and according to the second error value to obtain the optimized first initial external parameter as the third external parameter. The third error acquisition module can be used to obtain the camera reprojection error value of the corner point of the third calibration image according to the second initial external parameter between the preset camera and the calibration plate and the calibration plate parameters as the third error value. The second external parameter acquisition module can be used to optimize the second initial external parameter using the preset optimization algorithm and according to the third error value to obtain the optimized second initial external parameter as the second external parameter.

[0087] In this manner, the initial calibration parameters also include the intrinsic parameters of the preset optical machine and the distortion parameters of the preset optical machine, and the calibration device 300 of the projection device may further include: a fourth calibration image acquisition module and a first initial external parameter determination module. The fourth calibration image acquisition module may be used to obtain the optical machine reprojection error value of the corner point in the third calibration image according to the first initial external parameters between the preset optical machine and the calibration plate, the first external parameters and the calibration plate parameters, and then, by shooting the feature map of the preset optical machine of the preset projection device transmitted to the calibration plate through the preset camera of the preset projection device, to obtain the fourth calibration image. The first initial external parameter determination module may be specifically used to determine the first initial external parameters between the preset optical machine and the calibration plate according to the three-dimensional coordinate information of multiple feature points in the fourth calibration image in the first coordinate system, the two-dimensional coordinate information of the multiple feature points in the second coordinate system, the intrinsic parameters of the preset optical machine and the distortion parameters of the preset optical machine, wherein the first coordinate system is a three-dimensional coordinate system established based on the calibration plate, and the second coordinate system is a two-dimensional coordinate system established based on the imaging plane of the preset optical machine.

[0088] In this manner, the second error acquisition module can be specifically used to: obtain the first coordinate information of the corner point in the third calibration image in the first coordinate system according to the calibration plate parameters; convert the first coordinate information into the third coordinate system according to the first initial external parameter, the first external parameter, the internal parameter of the preset camera and the distortion parameter of the preset camera to obtain the third coordinate information of the corner point in the third coordinate system, where the third coordinate system is a two-dimensional coordinate system established based on the imaging plane of the camera; determine the optical-mechanical reprojection error value of the corner point in the third calibration image as the second error value according to the coordinate difference between the third coordinate information of the corner point in the third coordinate system and the preset coordinate information.

[0089] In some embodiments, the preset calibration parameters also include the intrinsic parameters of the preset camera and the distortion parameters of the preset camera, and the calibration device 300 of the projection device may further include: a second initial external parameter determination module. The second initial external parameter determination module may be specifically used to determine the second initial external parameter between the preset camera and the calibration plate according to the three-dimensional coordinate information of the corner point in the third calibration image in the first coordinate system, the two-dimensional coordinate information of the corner point in the third coordinate system, the intrinsic parameters of the preset camera and the distortion parameters of the preset camera before obtaining the camera reprojection error value of the corner point of the third calibration image as the third error value according to the second initial external parameters between the preset camera and the calibration plate and the calibration plate parameters, wherein the first coordinate system is a three-dimensional coordinate system established based on the calibration plate, and the third coordinate system is a two-dimensional coordinate system established based on the imaging plane of the camera.

[0090] In this manner, the second external parameter acquisition module can be specifically used to: obtain the first coordinate information of the corner point in the third calibration image in the first coordinate system based on the calibration plate parameters; convert the first coordinate information to the third coordinate system according to the second initial external parameter, the intrinsic parameter of the preset camera and the distortion parameter of the preset camera to obtain the second coordinate information of the corner point in the third coordinate system; determine the camera reprojection error value of the corner point in the third calibration image as the third error value according to the coordinate difference between the second coordinate information of the corner point in the third coordinate system and the preset coordinate information.

[0091] In some embodiments, the target projection device is placed on a preset base, the first error value includes a first sub-error value and a second sub-error value, the preset projection device includes a preset optical machine and a preset camera, the preset calibration parameters include the intrinsic parameters of the preset camera, the distortion parameters of the preset camera, the intrinsic parameters of the preset optical machine, the distortion parameters of the preset optical machine, the first external parameters between the preset camera and the preset optical machine, the second external parameters between the preset camera and the calibration plate, and the third external parameters between the preset optical machine and the calibration plate, the first external parameters include a first rotation parameter and a first translation parameter, the second external parameters include a second rotation parameter and a second translation parameter, and the third external parameters include a third rotation parameter and a third translation parameter.

[0092] In this manner, the iterative optimization module 340 can be specifically used to: utilize the preset optimization algorithm and, based on the first sub-error value, iteratively optimize the parameter values ​​of the internal parameters of the preset optical machine, the distortion parameters of the preset optical machine, and the third rotation parameters to obtain the internal parameters of the target optical machine, the distortion parameters of the target optical machine, and the rotation parameters of the target optical machine compared to the calibration plate; utilize the preset optimization algorithm and, based on the second sub-error value, iteratively optimize the parameter values ​​of the internal parameters of the preset camera, the distortion parameters of the preset camera, and the second rotation parameters to obtain the internal parameters of the target camera, the distortion parameters of the target camera, and the rotation parameters of the target camera compared to the calibration plate; obtain the rotation parameters and translation parameters between the target optical machine and the target camera based on the rotation parameters of the target optical machine compared to the calibration plate, the rotation parameters of the target camera compared to the calibration plate, the second translation parameters, and the third translation parameters.

[0093] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0094] In several embodiments provided in the present application, the coupling between modules may be electrical, mechanical or other forms of coupling.

[0095] In addition, each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above integrated modules can be implemented in the form of hardware or software functional modules.

[0096] In summary, a first calibration image is obtained by photographing a calibration plate with a target camera of a target projection device, a calibration pattern is provided on the calibration plate, and the target projection device also includes a target optical machine; preset calibration parameters of a preset projection device are obtained as initial calibration parameters of the target projection device, the preset projection device and the target projection device are of the same device type, the preset calibration parameters are obtained by calibrating the preset projection device based on a plurality of second calibration images in advance, and the plurality of second calibration images are obtained by photographing calibration plates of various postures by a preset camera of the preset projection device; according to the preset calibration parameters, the first calibration image and the calibration plate parameters, a reprojection error value of at least one corner point in the first calibration image is obtained as a first error value; using a preset optimization algorithm and according to the first error value, the parameter values ​​of the initial calibration parameters are iteratively optimized to obtain the optimized initial calibration parameters as the target calibration parameters of the target projection device. In this way, when calibrating the parameters of the target projection device, the calibration parameters obtained by accurately calibrating the preset projection device of the same device type as the target projection device are used as the initial calibration parameters of the target projection device; then, the preset optimization algorithm is used, and the reprojection error value of the corner point is combined to iteratively optimize the initial calibration parameters, which can improve the convergence speed and optimization accuracy of the preset optimization algorithm, thereby obtaining more accurate target calibration parameters of the target projection device more quickly.

[0097] The following will be combined Figure 8 An electronic device provided by the present application is described.

[0098] Reference Figure 8 , Figure 8 The structural block diagram of an electronic device 400 provided in an embodiment of the present application is shown, and the above method provided in an embodiment of the present application can be executed by the electronic device 400. The electronic device can be an electronic terminal with a data processing function, and the electronic terminal includes but is not limited to a smart phone, a tablet computer, a laptop computer, and a desktop computer.

[0099] The electronic device 400 in the embodiment of the present application may include one or more of the following components: a processor 401, a memory 402, and one or more applications, wherein the one or more applications may be stored in the memory 402 and configured to be executed by one or more processors 401, and the one or more programs are configured to execute the method as described in the aforementioned method embodiment.

[0100] The processor 401 may include one or more processing cores. The processor 401 uses various interfaces and lines to connect the various parts of the entire electronic device 400, and executes various functions and processes data of the electronic device 400 by running or executing instructions, programs, code sets or instruction sets stored in the memory 402, and calling data stored in the memory 402. Optionally, the processor 401 can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor 401 can integrate one or a combination of a central processing unit (Central Processing Unit, CPU), a graphics processing unit (Graphics Processing Unit, GPU) and a modem. Among them, the CPU mainly processes the operating system, user interface and application programs; the GPU is responsible for rendering and drawing display content; and the modem is used to process wireless communications. It can be understood that the above-mentioned modem can also be integrated into the processor 401 and implemented separately through a communication chip.

[0101] The memory 402 may include a random access memory (RAM) or a read-only memory (ROM). The memory 402 may be used to store instructions, programs, codes, code sets or instruction sets. The memory 402 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the following various method embodiments, etc. The data storage area may also store data (such as the various corresponding relationships described above) created by the electronic device 400 during use.

[0102] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0103] In several embodiments provided in the present application, the coupling or direct coupling or communication connection between the modules shown or discussed may be an indirect coupling or communication connection through some interfaces, devices or modules, which may be electrical, mechanical or other forms.

[0104] In addition, each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above integrated modules can be implemented in the form of hardware or software functional modules.

[0105] Please refer to Fig. 9 , which shows a structural block diagram of a computer-readable storage medium provided in an embodiment of the present application. The computer-readable medium 500 stores program codes, which can be called by a processor to execute the method described in the above method embodiment.

[0106] The computer readable storage medium 500 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk, or a ROM. Optionally, the computer readable storage medium 500 includes a non-transitory computer-readable storage medium. The computer readable storage medium 500 has storage space for program code 510 that performs any method step of the above method. These program codes can be read from or written to one or more computer program products. The program code 510 can be compressed, for example, in an appropriate form.

[0107] In some embodiments, a computer program product or computer program is provided, the computer program product or computer program includes computer instructions, the computer instructions are stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device performs the steps in the above-mentioned method embodiments.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for calibrating a projection device, It is characterized in that The projection device includes a camera and an optical machine, and the method includes: A first calibration image is obtained by photographing a calibration plate with a target camera of a target projection device, wherein a calibration pattern is provided on the calibration plate; Acquire preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device, the preset projection device and the target projection device being of the same device type, the preset calibration parameters being obtained by pre-calibrating the preset projection device based on a plurality of second calibration images, the plurality of second calibration images being obtained by taking a preset camera of the preset projection device for calibration plates in a variety of postures; According to the initial calibration parameters, the first calibration image and calibration plate parameters, obtaining a reprojection error value of at least one corner point in the first calibration image as a first error value; Using a preset optimization algorithm and according to the first error value, the parameter values ​​of the initial calibration parameters are iteratively optimized to obtain the optimized initial calibration parameters as the target calibration parameters of the target projection device.

2. The method according to claim 1, It is characterized in that The preset projection device includes a preset optical machine and a preset camera, the preset calibration parameters include a first external parameter between the preset camera and the preset optical machine, the preset projection device is placed on a preset base, the preset calibration parameters also include a second external parameter between the preset camera and the calibration plate, and a third external parameter between the preset optical machine and the calibration plate; The step of obtaining preset calibration parameters of a preset projection device includes: Using a preset camera of the preset projection device, photographing the calibration plate to obtain a third calibration image; According to the first initial extrinsic parameter between the preset optical machine and the calibration plate, the first extrinsic parameter and the calibration plate parameter, an optical machine reprojection error value of the corner point in the third calibration image is obtained as a second error value; Using the preset optimization algorithm and according to the second error value, optimizing the first initial extrinsic parameter to obtain an optimized first initial extrinsic parameter as the third extrinsic parameter; According to the second initial external parameter between the preset camera and the calibration plate and the calibration plate parameter, obtaining a camera reprojection error value of the corner point of the third calibration image as a third error value; The preset optimization algorithm is used to optimize the second initial extrinsic parameter according to the third error value to obtain an optimized second initial extrinsic parameter as the second extrinsic parameter.

3. The method according to claim 2, It is characterized in that The initial calibration parameters also include the intrinsic parameters of the preset optical machine and the distortion parameters of the preset optical machine; before obtaining the optical machine reprojection error value of the corner point in the third calibration image according to the first initial extrinsic parameter between the preset optical machine and the calibration plate, the first extrinsic parameter and the calibration plate parameter, the method includes: photographing, by a preset camera of the preset projection device, a characteristic image of the preset light machine of the preset projection device transmitted onto the calibration plate, to obtain a fourth calibration image; According to the three-dimensional coordinate information of multiple feature points in the fourth calibration image in the first coordinate system, the two-dimensional coordinate information of the multiple feature points in the second coordinate system, the intrinsic parameters of the preset optical machine and the distortion parameters of the preset optical machine, the first initial external parameters between the preset optical machine and the calibration plate are determined, the first coordinate system is a three-dimensional coordinate system established based on the calibration plate, and the second coordinate system is a two-dimensional coordinate system established based on the imaging plane of the preset optical machine.

4. The method according to claim 3, It is characterized in that The step of obtaining, according to the first initial extrinsic parameter between the preset optical machine and the calibration plate, the first extrinsic parameter, and the calibration plate parameter, a reprojection error value of the corner point in the third calibration image as a second error value, comprises: Acquire first coordinate information of corner points in the third calibration image in the first coordinate system according to the calibration plate parameters; According to the first initial external parameter, the first external parameter, the internal parameter of the preset camera, and the distortion parameter of the preset camera, the first coordinate information is converted into a third coordinate system to obtain third coordinate information of the corner point in the third coordinate system, where the third coordinate system is a two-dimensional coordinate system established based on an imaging plane of the camera; According to the coordinate difference between the third coordinate information of the corner point in the third coordinate system and the preset coordinate information, an optical-mechanical reprojection error value of the corner point in the third calibration image is determined as the second error value.

5. The method according to claim 2, It is characterized in that The preset calibration parameters also include the intrinsic parameters of the preset camera and the distortion parameters of the preset camera; Before obtaining the camera reprojection error value of the corner point of the third calibration image as the third error value according to the second initial external parameter between the preset camera and the calibration plate and the calibration plate parameter, the method further includes: The second initial external parameter between the preset camera and the calibration plate is determined according to the three-dimensional coordinate information of the corner point in the third calibration image in the first coordinate system, the two-dimensional coordinate information of the corner point in the third coordinate system, the intrinsic parameter of the preset camera and the distortion parameter of the preset camera, the first coordinate system is a three-dimensional coordinate system established based on the calibration plate, and the third coordinate system is a two-dimensional coordinate system established based on the imaging plane of the camera.

6. The method according to claim 5, It is characterized in that The acquiring, according to the second initial external parameter between the preset camera and the calibration plate and the calibration plate parameter, a camera reprojection error value of the corner point of the third calibration image as a third error value comprises: Based on the calibration plate parameters, obtaining first coordinate information of corner points in the third calibration image in the first coordinate system; According to the second initial external parameter, the internal parameter of the preset camera and the distortion parameter of the preset camera, the first coordinate information is converted into the third coordinate system to obtain the second coordinate information of the corner point in the third coordinate system; According to the coordinate difference between the second coordinate information of the corner point in the third coordinate system and the preset coordinate information, a camera reprojection error value of the corner point in the third calibration image is determined as the third error value.

7. The method according to any one of claims 1 to 6, It is characterized in that The target projection device and the preset projection device are placed on a preset base, the first error value includes a first sub-error value and a second sub-error value, the preset projection device includes a preset optical machine and a preset camera, the preset calibration parameters include an intrinsic parameter of the preset camera, a distortion parameter of the preset camera, an intrinsic parameter of the preset optical machine, a distortion parameter of the preset optical machine, a first extrinsic parameter between the preset camera and the preset optical machine, a second extrinsic parameter between the preset camera and the calibration plate, and a third extrinsic parameter between the preset optical machine and the calibration plate, the first extrinsic parameter includes a first rotation parameter and a first translation parameter, the second extrinsic parameter includes a second rotation parameter and a second translation parameter, and the third extrinsic parameter includes a third rotation parameter and a third translation parameter; The using of a preset optimization algorithm and iteratively optimizing the parameter value of the initial calibration parameter according to the first error value to obtain the optimized initial calibration parameter as the target calibration parameter of the target projection device includes: Using the preset optimization algorithm and according to the first sub-error value, iteratively optimizing the intrinsic parameters of the preset optical machine, the distortion parameters of the preset optical machine, and the parameter value of the third rotation parameter, to obtain the intrinsic parameters of the target optical machine, the distortion parameters of the target optical machine, and the rotation parameters of the target optical machine compared to the calibration plate; Using the preset optimization algorithm and according to the second sub-error value, iteratively optimizing the intrinsic parameters of the preset camera, the distortion parameters of the preset camera, and the parameter values ​​of the second rotation parameters, to obtain the intrinsic parameters of the target camera, the distortion parameters of the target camera, and the rotation parameters of the target camera compared to the calibration plate; The rotation parameters and translation parameters between the target optical machine and the target camera are obtained according to the rotation parameters of the target optical machine compared to the calibration plate, the rotation parameters of the target camera compared to the calibration plate, the second translation parameters and the third translation parameters.

8. A calibration device for a projection device, It is characterized in that The projection device includes a camera and an optical machine, and the device includes: An image shooting module, used for shooting a calibration plate with a target camera of a target projection device to obtain a first calibration image, wherein a calibration pattern is arranged on the calibration plate; an initial parameter acquisition module, used to acquire preset calibration parameters of a preset projection device as initial calibration parameters of the target projection device, the preset projection device and the target projection device being of the same device type, the preset calibration parameters being obtained by calibrating the preset projection device based on a plurality of second calibration images in advance, the plurality of second calibration images being obtained by taking a preset camera of the preset projection device for calibration plates of various postures; an error value acquisition module, configured to acquire, according to the initial calibration parameters, the first calibration image and calibration plate parameters, a reprojection error value of at least one corner point in the first calibration image as a first error value; The iterative optimization module is used to iteratively optimize the parameter value of the initial calibration parameter by using a preset optimization algorithm and according to the first error value, so as to obtain the optimized initial calibration parameter as the target calibration parameter of the target projection device.

9. An electronic device, It is characterized in that The electronic device comprises: Memory; One or more processors coupled to the memory; One or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores program code, and the program code can be called by a processor to execute the method as claimed in any one of claims 1 to 7.

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