A method, device, medium and equipment for determining a field of view angle of a camera module

Abstract

The application provides a method, device, medium and equipment for determining the field of view angle of a camera module, the method comprising: obtaining the internal parameters of the camera module which have been pre-calibrated; rectifying the key points of a target image by using the internal parameters to obtain corresponding target points; and determining the field of view angle of the camera module according to the coordinates of the target points and the internal parameters. In this way, the key points of the target image are rectified by using the internal parameters of the camera module, so that the target points obtained after rectification, the optical center and any point on the light rays located at the corners of the field of view angle in the real three-dimensional space remain collinear, thereby the corresponding field of view angle is accurately determined by using the Pythagorean theorem based on the distance between two target points and the focal length. Compared with the method for calculating the FOV based on the shooting distance in the real space and the length of the grid background image in the prior art, the application can reduce the error of external measurement environmental factors, and thus helps to improve the measurement accuracy of the FOV.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lens parameter determination, in particular to a method and device for determining the field of view of a camera module, a medium and equipment. BACKGROUND

[0002] With the continuous development of technology, users have higher and higher requirements for the performance of camera modules. The field of view (FOV) of a lens is an important performance indicator. FOV refers to the angle formed by the upper and lower or left and right or diagonal boundaries of a three-dimensional world from the perspective of a camera and the optical center point of the lens, which corresponds to the longitudinal FOV, the lateral FOV and the diagonal FOV, respectively.

[0003] Before a camera module is put into use, the FOV needs to be measured and calibrated. In the traditional technology, the main method for measuring the FOV is to arrange a large-area plane grid in space, and then shoot the plane by a camera, and calculate the FOV according to the number or proportion of the grid in the image. However, this testing method not only requires a large-area testing environment, but also requires the camera module to face the plane grid directly, which has high testing requirements and large measurement error.

[0004] Therefore, there is an urgent need for a method for measuring the FOV of a camera module to improve the measurement accuracy of the FOV. SUMMARY

[0005] To solve or partially solve the technical problem that the measurement error of the FOV of a camera module is large in the prior art, thereby affecting the overall quality of the camera module, the embodiments of the present application provide a method and device for determining the field of view of a camera module, a medium and equipment.

[0006] In a first aspect, the present application provides a method for determining the field of view of a camera module, the method comprising:

[0007] obtaining the internal parameters of the camera module which are calibrated in advance;

[0008] correcting the key points of a target image by using the internal parameters to obtain corresponding target points; the target image is an image obtained by shooting a chart by using the camera module;

[0009] determining the field of view of the camera module according to the coordinates of the target points and the internal parameters.

[0010] In the above scheme, the internal parameters include the principal point coordinates, the focal length, the radial distortion parameters and the tangential distortion parameters; the correction of the key points of the target image by using the internal parameters to obtain the corresponding target points comprises:

[0011] For any key point, a current coordinate of the key point is obtained; the current coordinate comprises a current horizontal coordinate and a current vertical coordinate;

[0012] Based on the formula And the formula The current horizontal coordinate x and the current vertical coordinate y are processed by using a least square optimization algorithm to obtain a corresponding least square optimal solution; the least square optimal solution is a horizontal coordinate x' of the target point and a vertical coordinate y' of the target point; wherein,

[0013] The k1 is a first radial distortion parameter, the k2 is a second radial distortion parameter, the k3 is a third radial distortion parameter, the k4 is a fourth radial distortion parameter, the k5 is a fifth radial distortion parameter, the k6 is a sixth radial distortion parameter, the r is a distance between a principal point and the target point, the s1 is the first tangential distortion parameter, and the s2 is the second tangential distortion parameter.

[0014] In the above scheme, the field of view of the camera module is determined according to the coordinates of the target point and the intrinsic parameters, comprising:

[0015] When the field of view is a horizontal field of view, the coordinates of a first target point and the coordinates of a second target point are obtained; the first target point is obtained by performing distortion correction on a first key point, and the second target point is obtained by performing distortion correction on a second key point; the first key point is a midpoint of a left boundary of a target image, and the second key point is a midpoint of a right boundary of the target image;

[0016] A first distance between the first target point and the second target point is determined according to the coordinates of the first target point and the coordinates of the second target point;

[0017] According to A horizontal field of view FOV1 of the camera module is determined; wherein, the d1 is the first distance, and the f is the focal length.

[0018] In the above scheme, the field of view of the camera module is determined according to the coordinates of the target point and the intrinsic parameters, comprising:

[0019] When the field of view is a vertical field of view, the coordinates of a third target point and the coordinates of a fourth target point are obtained; the third target point is obtained by performing distortion correction on a third key point, and the fourth target point is obtained by performing distortion correction on a fourth key point; the third key point is a midpoint of an upper boundary of a target image, and the fourth key point is a midpoint of a lower boundary of the target image;

[0020] determine a second distance between the third target point and the fourth target point according to the coordinate of the third target point and the coordinate of the fourth target point;

[0021] According to determine a longitudinal field of view FOV2 of the camera module; wherein the d2 is the second distance, and the f is the focal length.

[0022] In the above scheme, the field of view of the camera module is determined according to the coordinate of the target point and the intrinsic parameter, comprising:

[0023] When the field of view is a diagonal field of view, the coordinate of a fifth target point and the coordinate of a sixth target point are obtained; the fifth target point is obtained by distortion correction on a fifth key point, the sixth target point is obtained by distortion correction on a fourth key point, and the fifth key point and the sixth key point are vertices on a diagonal line of the target image;

[0024] determine a third distance between the fifth target point and the sixth target point according to the coordinate of the fifth target point and the coordinate of the sixth target point;

[0025] According to determine a diagonal field of view FOV3 of the camera module; wherein the d3 is the third distance, and the f is the focal length.

[0026] In a second aspect of the present application, a device for determining the field of view of a camera module is provided, comprising:

[0027] An acquisition unit is configured to acquire the intrinsic parameter of the camera module pre-calibrated;

[0028] A correction unit is configured to correct the key point of a target image by using the intrinsic parameter to obtain a corresponding target point; the target image is an image obtained by photographing a chart by using the camera module;

[0029] A determination unit is configured to determine the field of view of the camera module according to the coordinate of the target point and the intrinsic parameter.

[0030] In the above scheme, the intrinsic parameter comprises a principal point coordinate, a focal length, a radial distortion parameter and a tangential distortion parameter; and the correction unit is specifically configured to:

[0031] For any key point, the current coordinate of the key point is acquired; the current coordinate comprises a current horizontal coordinate and a current vertical coordinate;

[0032] based on the formula and the formula The current abscissa x and the current ordinate y are processed by using a least square optimization algorithm to obtain a corresponding least square optimal solution; the least square optimal solution is an abscissa x' of the target point and an ordinate y' of the target point; wherein,

[0033] The k1 is a first radial distortion parameter, the k2 is a second radial distortion parameter, the k3 is a third radial distortion parameter, the k4 is a fourth radial distortion parameter, the k5 is a fifth radial distortion parameter, the k6 is a sixth radial distortion parameter, the r is a distance between a principal point and the target point, the s1 is the first tangential distortion parameter, and the s2 is the second tangential distortion parameter.

[0034] In the scheme, the determination unit is specifically configured to:

[0035] When the field of view angle is a lateral field of view angle, coordinates of a first target point and coordinates of a second target point are obtained; the first target point is obtained by performing distortion correction on a first key point, and the second target point is obtained by performing distortion correction on a second key point; the first key point is a midpoint of a left boundary of a target image, and the second key point is a midpoint of a right boundary of the target image.

[0036] A first distance between the first target point and the second target point is determined according to the coordinates of the first target point and the coordinates of the second target point.

[0037] According to A lateral field of view angle FOV1 of the camera module is determined; wherein the d1 is the first distance, and the f is the focal length.

[0038] In a third aspect of the present application, a computer readable storage medium is provided, which stores a computer program, and the program is executed by a processor to implement the steps of the method in any one of the first aspect.

[0039] In a fourth aspect of the present application, a computer device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method in any one of the first aspect when executing the program.

[0040] The application provides a method, device, medium and equipment for determining a field of view angle of a camera module, the method comprising: acquiring internal parameters of the camera module which are calibrated in advance; correcting key points of a target image by using the internal parameters to obtain corresponding target points; the target image is an image obtained by photographing a chart by using the camera module; and determining the field of view angle of the camera module according to the coordinates of the target points and the internal parameters. In this way, the key points of the target image are corrected by using the internal parameters of the camera module, so that the target points obtained after correction, the optical center and any point on the light rays at the corners of the field of view angle in the real three-dimensional space are kept collinear, thereby the corresponding field of view angle is accurately determined by using the Pythagorean theorem based on the distance between two target points and the focal length. Compared with the method for calculating the FOV based on the photographing distance in the real space and the length of the grid background image in the prior art, the application can reduce the error of external measurement environmental factors, and therefore helps to improve the measurement accuracy of the FOV. BRIEF DESCRIPTION OF DRAWINGS

[0041] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Moreover, the same reference numerals in different figures represent the same or similar components. In the drawings:

[0042] Figure 1 A flowchart of a method for determining a field of view angle of a camera module according to an embodiment of the application is shown;

[0043] Figure 2 A two-dimensional view diagram for correcting each key point in a target image to obtain a corresponding target point according to an embodiment of the application is shown;

[0044] Figure 3 A one-dimensional view diagram for correcting a certain key point to obtain a target point according to an embodiment of the application is shown;

[0045] Figure 4 A structure diagram of a device for determining a field of view angle of a camera module according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0046] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0047] The application provides a method for determining a field of view angle of a camera module, as shown in the accompanying drawings. Figure 1 The method mainly comprises the following steps:

[0048] S110, obtaining pre-calibrated intrinsic parameters of the camera module;

[0049] The intrinsic parameter calibration method for the camera module can be arbitrarily selected. For example, the intrinsic parameters of the camera module can be calibrated by using Zhang Zhengyou's flat plate calibration algorithm. The method mainly uses the camera module to capture multiple chart images at different positions, extracts corner points in each image by using a corner point extraction algorithm, constructs a 2D-3D pose relationship according to the corner points, and calculates the intrinsic parameters of the camera module by calling an intrinsic parameter calibration function in opencv according to the pose relationship.

[0050] In this step, the application mainly aims to obtain pre-calibrated intrinsic parameters of the camera module, and the intrinsic parameter calibration algorithm is not limited.

[0051] After the intrinsic parameters are calibrated, the intrinsic parameters of the camera module can be directly obtained. The intrinsic parameters include a principal point coordinate (the coordinate of the intersection of the optical center and the sensor when the optical center is perpendicular to the sensor), a focal length, a radial distortion parameter, and a tangential distortion parameter.

[0052] The radial distortion parameters include a first radial distortion parameter k1, a second radial distortion parameter k2, a third radial distortion parameter k3, a fourth radial distortion parameter k4, a fifth radial distortion parameter k5, and a sixth radial distortion parameter k6.

[0053] The tangential distortion parameters include a first tangential distortion parameter p1 and a second tangential distortion parameter p2.

[0054] S111, correcting the key points of a target image by using the intrinsic parameters to obtain corresponding target points; the target image is an image obtained by capturing a chart by using the camera module;

[0055] In this step, the target image is an image obtained by capturing a chart by using the camera module, and the chart can be understood as a black and white checkerboard. For an original target image without distortion correction, the FOV boundary in the three-dimensional world corresponds to the boundary of the target image. Therefore, the key points of the target image are the four vertices and the midpoints of the upper, lower, left, and right boundaries of the target image.

[0056] In an embodiment, the method for correcting the key points of the target image by using the intrinsic parameters to obtain corresponding target points comprises:

[0057] For any key point, obtain the current coordinates of the key point; the current coordinates include: the current horizontal coordinate and the current vertical coordinate;

[0058] Based on the formula and formula The current horizontal coordinate x and the current vertical coordinate y are processed using a least squares optimization algorithm to obtain a corresponding least squares optimal solution; the least squares optimal solution is the horizontal coordinate x′ and the vertical coordinate y′ of the target point; wherein,

[0059] k1 is the first radial distortion parameter, k2 is the second radial distortion parameter, k3 is the third radial distortion parameter, k4 is the fourth radial distortion parameter, k5 is the fifth radial distortion parameter, k6 is the sixth radial distortion parameter, r is the distance between the principal point and the target point, s1 is the first tangential distortion parameter, and s2 is the second tangential distortion parameter.

[0060] Specifically, for the target image, each pixel has unique coordinates, so the position of each key point in the target image can also be directly obtained. Once the coordinates of each key point are determined, the least squares optimal solution can be determined based on the above formula and the least squares optimization algorithm (the solution process is equivalent to optimizing the coordinates of the target point based on the current coordinates to ultimately obtain the optimal solution), thereby obtaining the coordinates of the corresponding target point.

[0061] S112: Determine the field of view angle of the camera module according to the coordinates of the target point and the intrinsic parameters.

[0062] After the coordinates of each target point are determined, the field of view of the camera module can be determined based on the coordinates of the target point and the intrinsic parameters. Figure 2 As shown in , after the distortion correction of the 8 key points of the target image, the target points are obtained as follows Figure 2 As shown. Figure 2 In , p1~p8 are key points, and p1′~p8′ are corresponding target points.

[0063] Since the field of view angle includes the horizontal field of view angle, the vertical field of view angle and the diagonal field of view angle, it is necessary to determine the above three field of view angles of the camera module. In one embodiment, the field of view angle of the camera module is determined according to the coordinates of the target point and the intrinsic parameters, including:

[0064] When the field of view angle is a horizontal field of view angle, the coordinates of the first target point and the coordinates of the second target point are obtained; the first target point is obtained by performing distortion correction on the first key point, and the second target point is obtained by performing distortion correction on the second key point. The first key point is the midpoint of the left boundary of the target image, and the second key point is the midpoint of the right boundary of the target image;

[0065] determine a first distance between the first target point and the second target point according to the coordinate of the first target point and the coordinate of the second target point;

[0066] According to determine a lateral field of view FOV1 of the camera module; wherein d1 is the first distance, and f is the focal length.

[0067] Specifically, as Figure 3 shown, assuming that the first key point is p1, the first target point is p1', the second key point is p2, the second target point is p'2, A1 is an arbitrary point on the FOV edge angle light, B1 is an arbitrary point on the other edge angle light of the FOV, and the optical center is OC, then the lateral FOV is indicated by the θ angle in Figure 3 It can be seen from Figure 3 that θ = 2β, so if β can be determined, the lateral FOV can be determined.

[0068] After the first key point and the second key point are corrected, the first target point, the optical center OC and the A1 point are collinear, assuming that the first distance between p1' and p'2 is d1, then

[0069]

[0070] Further, we can get:

[0071]

[0072] In this way, the lateral FOV is determined.

[0073] Similarly, according to the coordinates of the target points and the internal parameters, the field of view of the camera module is determined, including:

[0074] When the field of view is a longitudinal field of view, the coordinate of a third target point and the coordinate of a fourth target point are obtained; the third target point is obtained by correcting a third key point, and the fourth target point is obtained by correcting a fourth key point; the third key point is the midpoint of the upper boundary of the target image, and the fourth key point is the midpoint of the lower boundary of the target image;

[0075] determine a second distance between the third target point and the fourth target point according to the coordinate of the third target point and the coordinate of the fourth target point;

[0076] According to determine a longitudinal field of view FOV2 of the camera module; wherein d2 is the second distance, and f is the focal length.

[0077] Since the longitudinal field of view angle is the field of view angle in the up-down direction, the longitudinal field of view angle needs to be determined according to the midpoint of the upper boundary of the target image and the midpoint of the lower boundary of the target image. The specific determination principle is the same as that of the determination principle of the transverse field of view angle, and thus will not be described here.

[0078] In an embodiment, the field of view angle of the camera module is determined according to the coordinates of the target points and the internal parameters, comprising:

[0079] When the field of view angle is the diagonal field of view angle, the coordinates of the fifth target point and the coordinates of the sixth target point are obtained; the fifth target point is obtained by performing distortion correction on the fifth key point, and the sixth target point is obtained by performing distortion correction on the fourth key point; the fifth key point and the sixth key point are the vertices on the diagonal of the target image;

[0080] A third distance between the fifth target point and the sixth target point is determined according to the coordinates of the fifth target point and the coordinates of the sixth target point;

[0081] According to A diagonal field of view angle FOV3 of the camera module is determined; wherein d3 is the third distance, and f is the focal length.

[0082] Since the diagonal field of view angle is the field of view angle in the diagonal direction, the diagonal field of view angle needs to be determined according to the two vertices on the diagonal of the target image. The specific determination principle is the same as that of the determination principle of the transverse field of view angle, and thus will not be described here.

[0083] It should be noted that the target image has two diagonals, and the diagonal field of view angle can be determined using the two vertices on any one of the diagonals. For example, referring to Figure 2 When the fifth key point is p5, the sixth key point is p6; when the seventh key point is p7, the eighth key point is p8.

[0084] Through the above method, the transverse FOV, the longitudinal FOV and the diagonal FOV of the camera module can be finally determined.

[0085] The internal parameters of the camera module are used to perform distortion correction on the key points of the target image in the present application, so that the target points obtained after correction, the optical center and any point in the real three-dimensional space on the light rays at the corners of the field of view angle are kept collinear, thereby the corresponding field of view angle is accurately determined based on the distance between the two target points and the focal length by using the Pythagorean theorem. Compared with the prior art which calculates the FOV based on the shooting distance in the real space and the length of the grid background image, the present application can reduce the error of external measurement environmental factors, and thus helps to improve the measurement accuracy of the FOV.

[0086] Based on the same inventive concept as in the foregoing embodiments, the present embodiment also provides a device for determining the field of view angle of a camera module, like Figure 4As shown, the device comprises:

[0087] The acquisition unit 41 is configured to acquire the internal parameters of the camera module which are pre-calibrated.

[0088] The correction unit 42 is configured to correct the key points of a target image by using the internal parameters to obtain corresponding target points; the target image is an image obtained by capturing a chart by using the camera module.

[0089] The determination unit 43 is configured to determine the field of view angle of the camera module according to the coordinates of the target points and the internal parameters.

[0090] In an embodiment, the internal parameters include principal point coordinates, focal length, radial distortion parameters and tangential distortion parameters; and the correction unit 42 is specifically configured to:

[0091] For any key point, the current coordinates of the key point are acquired; the current coordinates include a current horizontal coordinate and a current vertical coordinate.

[0092] based on the formula and the formula The current horizontal coordinate x and the current vertical coordinate y are processed by using a least square optimization algorithm to obtain corresponding least square optimal solutions; the least square optimal solutions are a horizontal coordinate x' of the target point and a vertical coordinate y' of the target point; wherein,

[0093] The k1 is a first radial distortion parameter, the k2 is a second radial distortion parameter, the k3 is a third radial distortion parameter, the k4 is a fourth radial distortion parameter, the k5 is a fifth radial distortion parameter, the k6 is a sixth radial distortion parameter, the r is a distance between the principal point and the target point, the s1 is the first tangential distortion parameter, and the s2 is the second tangential distortion parameter.

[0094] The determination unit 43 is specifically configured to:

[0095] When the field of view angle is a horizontal field of view angle, the coordinates of a first target point and the coordinates of a second target point are acquired; the first target point is obtained by correcting a first key point, the second target point is obtained by correcting a second key point, the first key point is a midpoint of a left boundary of the target image, and the second key point is a midpoint of a right boundary of the target image.

[0096] A first distance between the first target point and the second target point is determined according to the coordinates of the first target point and the coordinates of the second target point.

[0097] According to Determine a lateral field of view angle FOV1 of the camera module; wherein the d1 is the first distance, and the f is the focal length.

[0098] Since the device introduced in the embodiments of the present application is the device used in the method for determining the field of view angle of the camera module, the specific structure and deformation of the device can be understood by those skilled in the art based on the method introduced in the embodiments of the present application, and thus will not be described here. Any device used in the method of the embodiments of the present application belongs to the scope of the present application.

[0099] Based on the same inventive concept, the present embodiment provides a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any step of the method described above.

[0100] Based on the same inventive concept, the present embodiment provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the steps of any method described above.

[0101] Through one or more embodiments of the present application, the present application has the following advantages or benefits:

[0102] The present application provides a method, device, medium and equipment for determining the field of view angle of a camera module, the method comprising: obtaining the internal parameters of the camera module which are pre-calibrated; using the internal parameters to correct the key points of a target image to obtain corresponding target points; the target image is an image obtained by photographing a chart using the camera module; determining the field of view angle of the camera module according to the coordinates of the target points and the internal parameters; in this way, the internal parameters of the camera module are used to correct the key points of the target image, so that the target points obtained after correction, the optical center and any point in the real three-dimensional space on the light rays at the corners of the field of view angle remain collinear, thereby based on the distance between two target points and the focal length, the corresponding field of view angle is accurately determined using the Pythagorean theorem; compared with the way of calculating FOV based on the shooting distance in the real space and the length of the grid background image in the prior art, the present application can reduce the error of external measurement environmental factors, and thus helps to improve the measurement accuracy of FOV.

[0103] The algorithms and displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems can be used with programs in accordance with the teachings herein, or it can prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will be apparent from the description above. In addition, the present application is not intended to be limited to any particular programming language. It will be appreciated that there are many programming languages that can be used to implement the teachings herein, and any such programming language can be used.

[0104] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order not to obscure the understanding of this description.

[0105] Similarly, it is to be understood that the phraseology or terminology employed herein, and not otherwise specifically defined herein, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading the technical description. The description, aspects, and embodiments of the present application are to be considered in the context of the entire disclosure and any separate aspect or embodiment disclosed herein can be combined with any or all other disclosed aspects or embodiments.

[0106] Those skilled in the art will appreciate that the modules in the apparatuses in the embodiments can be adapted and placed in one or more apparatuses other than the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and further can be divided into multiple sub-modules or sub-units or sub-components. Any combination of all disclosed features in the specification (including the accompanying claims, abstract and drawings) and any method or apparatus so disclosed can be made, except that at least some of such features and / or processes or units are mutually exclusive, unless explicitly stated otherwise. Each feature disclosed in the specification (including the accompanying claims, abstract and drawings) can be replaced by alternative features serving the same, equivalent or similar purpose, unless explicitly stated otherwise.

[0107] Further, those skilled in the art will appreciate that a combination of features of different embodiments can be meant to be within the scope of the application and form a different embodiment, although some embodiments include certain features but not others that are included in other embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0108] The various component embodiments of the present application can be implemented in hardware, or as software modules running in one or more processors, or in combinations thereof. As will be appreciated by one skilled in the art, a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functionality of some or all of the components in the gateway, proxy server, system according to embodiments of the present application. The present application can also be implemented as a program of instructions for performing part or all of the methods described herein, e.g., a computer program and a computer program product. Such program of the present application can be stored on a computer readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier medium, or in any other form.

[0109] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the system claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The use of the word 'at least' followed by a list of one or more items means that any item in the list can be present or there can be more than one of a certain item. The use of the terms first, second and third, etc. does not imply any order in time or in quality but rather is used for the purpose of naming various elements.

[0110] Although the preferred embodiments of the application have been described, those skilled in the art will be able to make additional changes and modifications thereto without departing from the scope of the application. Accordingly, the appended claims are intended to cover all such changes and modifications that fall within the scope of the application.

[0111] The above-described embodiments are merely intended to illustrate the present application, but not to limit the scope of the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall fall within the scope of the present application.

Claims

1. A method for determining the field of view angle of a camera module, characterized in that: The method comprises: Obtaining the pre-calibrated intrinsic parameters of the camera module; the intrinsic parameters include: focal length; Using the intrinsic parameters, distortion correction is performed on at least one pair of key points of a target image to obtain a corresponding pair of target points; the target image is an image obtained by photographing a chart using the camera module; and the key points are points on the boundary of the target image; The distance between the pair of target points is determined according to the coordinates of the pair of target points, and the field of view angle of the camera module is determined according to the distance and the focal length.

2. The method according to claim 1, wherein The intrinsic parameters further include: principal point coordinates, radial distortion parameters, and tangential distortion parameters; and using the intrinsic parameters to perform distortion correction on at least one pair of key points of the target image to obtain corresponding target points includes: For any of the key points, obtain the current coordinates of the key point; the current coordinates include: a current horizontal coordinate and a current vertical coordinate; Based on the formula and formula The current horizontal coordinate x and the current vertical coordinate y are processed using a least squares optimization algorithm to obtain a corresponding least squares optimal solution; the least squares optimal solution is the horizontal coordinate x′ and the vertical coordinate y′ of the target point; wherein, The k1 is a first radial distortion parameter, the k2 is a second radial distortion parameter, the k3 is a third radial distortion parameter, the k4 is a fourth radial distortion parameter, the k5 is a fifth radial distortion parameter, the k6 is a sixth radial distortion parameter, the r is a distance between the principal point and the target point, the s1 is a first tangential distortion parameter, and the s2 is a second tangential distortion parameter.

3. The method according to claim 1, wherein The determining the distance between the pair of target points according to the coordinates of the pair of target points, and determining the field of view angle of the camera module according to the distance and the focal length, includes: When the field of view angle is a horizontal field of view angle, obtaining coordinates of a first target point and a second target point; the first target point is obtained by performing distortion correction on the first key point, and the second target point is obtained by performing distortion correction on the second key point, the first key point is the midpoint of the left boundary of the target image, and the second key point is the midpoint of the right boundary of the target image; determining a first distance between the first target point and the second target point according to the coordinates of the first target point and the coordinates of the second target point; according to Determine the lateral field of view FOV1 of the camera module; wherein d1 is the first distance, and f is the focal length.

4. The method according to claim 1, wherein The determining the distance between the pair of target points according to the coordinates of the pair of target points, and determining the field of view angle of the camera module according to the distance and the focal length, includes: When the field of view angle is a longitudinal field of view angle, obtaining coordinates of a third target point and a fourth target point; the third target point is obtained by performing distortion correction on the third key point, the fourth target point is obtained by performing distortion correction on the fourth key point, the third key point is the midpoint of the upper boundary of the target image, and the fourth key point is the midpoint of the lower boundary of the target image; determining a second distance between the third target point and the fourth target point according to the coordinates of the third target point and the coordinates of the fourth target point; according to Determine the longitudinal field of view FOV2 of the camera module; wherein d2 is the second distance and f is the focal length.

5. The method according to claim 1, wherein The determining the distance between the pair of target points according to the coordinates of the pair of target points, and determining the field of view angle of the camera module according to the distance and the focal length, includes: When the field of view angle is a diagonal field of view angle, obtaining coordinates of a fifth target point and a sixth target point; the fifth target point is obtained by performing distortion correction on the fifth key point, and the sixth target point is obtained by performing distortion correction on the sixth key point, and the fifth key point and the sixth key point are vertices on the diagonal line of the target image; determining a third distance between the fifth target point and the sixth target point according to the coordinates of the fifth target point and the coordinates of the sixth target point; according to Determine the diagonal field of view FOV3 of the camera module; wherein d3 is the third distance and f is the focal length.

6. A device for determining the field of view angle of a camera module, characterized in that: The device comprises: An acquisition unit, configured to acquire pre-calibrated intrinsic parameters of the camera module; the intrinsic parameters include: focal length; a correction unit, configured to perform distortion correction on at least one pair of key points of a target image using the intrinsic parameters to obtain a corresponding pair of target points; the target image is an image obtained by photographing a chart using the camera module; and the key points are points on the boundary of the target image; A determination unit is used to determine the distance between the pair of target points according to the coordinates of the pair of target points, and to determine the field of view of the camera module according to the distance and the focal length.

7. The device according to claim 6, characterized in that The internal parameters also include: principal point coordinates, radial distortion parameters and tangential distortion parameters; the correction unit is specifically used to: For any of the key points, obtain the current coordinates of the key point; the current coordinates include: a current horizontal coordinate and a current vertical coordinate; Based on the formula and formula The current horizontal coordinate x and the current vertical coordinate y are processed using a least squares optimization algorithm to obtain a corresponding least squares optimal solution; the least squares optimal solution is the horizontal coordinate x′ and the vertical coordinate y′ of the target point; wherein, The k1 is a first radial distortion parameter, the k2 is a second radial distortion parameter, the k3 is a third radial distortion parameter, the k4 is a fourth radial distortion parameter, the k5 is a fifth radial distortion parameter, the k6 is a sixth radial distortion parameter, the r is a distance between the principal point and the target point, the s1 is a first tangential distortion parameter, and the s2 is a second tangential distortion parameter.

8. The device according to claim 6, wherein The determining unit is specifically configured to: When the field of view angle is a horizontal field of view angle, obtaining coordinates of a first target point and a second target point; the first target point is obtained by performing distortion correction on the first key point, and the second target point is obtained by performing distortion correction on the second key point, the first key point is the midpoint of the left boundary of the target image, and the second key point is the midpoint of the right boundary of the target image; determining a first distance between the first target point and the second target point according to the coordinates of the first target point and the coordinates of the second target point; according to Determine the lateral field of view FOV1 of the camera module; wherein d1 is the first distance, and f is the focal length.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 5 are implemented.

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