Camera field of view testing device and testing method thereof

Abstract

This invention relates to the field of optical imaging testing, and more particularly to a camera field of view testing device and method. The method includes first acquiring a calibration image and a test image; calibrating the distortion parameters of the vehicle-mounted camera using the calibration image; and using these distortion parameters to correct the distortion of the subsequent test image used for field of view calculation, resulting in a distortion-free test image. On the distortion-free test image, the full field of view of the camera under test is calculated based on angle markings with known angle values. This invention innovatively employs a calibration-correction-calculation approach to test the camera's field of view, fundamentally eliminating the influence of distortion factors on the measurement results, achieving a breakthrough in technical principles, and thus improving the accuracy of field of view testing.

Description

Technical Field

[0001] This invention belongs to the field of optical imaging testing technology, and particularly relates to a camera field of view testing device and its testing method. Background Technology

[0002] With the rapid development of intelligent driving technology, vehicle cameras have become one of the core sensors for environmental perception. To improve the reliability and safety of Advanced Driving Assistance Systems (ADAS), vehicle cameras must undergo rigorous performance testing before installation in vehicles. Among these tests, the field of view (FOV), as a core parameter of the vehicle camera, directly determines the vehicle's environmental perception range.

[0003] Currently, the testing methods for camera field of view are mainly divided into two categories.

[0004] The first category is based on methods using precision mechanical angle measurements, such as the use of a high-precision turntable. This type of method involves fixing a vehicle-mounted camera to the turntable and measuring the boundary angles from which a clear image can be formed, thus directly reading the field of view value. While this method offers high accuracy, the equipment is expensive and the testing efficiency is low, making it difficult to meet the rapid testing needs of high-volume production lines.

[0005] The second category is the planar target method based on image analysis. This type of method involves photographing a planar chart with a specific pattern (such as a central square, crosshairs, or a checkerboard pattern), calculating the pixel equivalent using known dimensions, and then using trigonometric functions to calculate the field of view based on the shooting distance. This method has lower equipment costs and is relatively simple to operate, so it is widely used in the daily testing and production line inspection of cameras.

[0006] However, the aforementioned planar target method has a fundamental technical flaw: it fails to effectively handle optical distortion. Wide-angle automotive cameras with large field of view typically exhibit significant radial distortion, manifesting as barrel or pincushion distortion. The presence of radial distortion causes nonlinear displacement of pixels in image edge regions: in barrel distortion, edge object pixels shrink towards the image center; in pincushion distortion, edge pixels stretch outwards. Existing planar target methods rely on the assumption that the imaging system approximately conforms to a pinhole model, i.e., ignoring radial distortion or considering it negligible. This assumption often fails for wide-angle automotive cameras with large field of view. Radial distortion leads to two serious problems: First, it introduces calibration errors. When the reference graphic (such as a square) used to calculate the physical size of pixels is located at the edge of the image, the coordinates of its corner points shift due to distortion, causing the calculated pixel equivalent to deviate from the actual value, which in turn affects the accuracy of the field of view calculation.

[0007] Secondly, misjudgment of the field of view boundary occurs. The real-world angle corresponding to the outermost effective pixel in the image deviates from the theoretical value due to pixel compression or stretching caused by distortion. It is difficult to accurately distinguish between "the imaging boundary determined by the field of view angle" and "the image deformation caused by distortion", especially when measuring the diagonal or edge field of view angles, the accuracy of the test results is difficult to guarantee.

[0008] Therefore, existing technologies cannot eliminate the impact of radial distortion on the accuracy of field-of-view measurement when testing wide-angle automotive cameras with large field of view, and the test results are difficult to meet the requirements of high-precision calibration and quality control for automotive cameras. How to provide a method that can effectively isolate distortion factors and achieve high-precision measurement of the field of view has become an urgent technical problem to be solved in this field. Summary of the Invention

[0009] In view of this, the present invention aims to provide a camera field of view testing device and method to solve the technical problem that the existing planar target method cannot effectively eliminate the radial distortion of the lens, thus affecting the accuracy of the field of view test.

[0010] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A camera field of view testing device, comprising: The planar target unit is used to provide calibration images and test images for the camera under test. The calibration image is used to calibrate the distortion parameters of the camera under test, and the test image is used to measure the field of view of the camera under test. Angle marks with known angle values ​​are set on the planar target unit. A cylindrical target unit is used to provide test images for the camera under test. The test images are used to measure the field of view of the camera under test. Angle marks with known angle values ​​are set on the cylindrical target unit. A rotating mechanism, connected to a planar target unit, is used to drive the planar target unit to rotate relative to the camera under test at least three different angular positions.

[0011] Furthermore, the planar target unit includes a planar target plate, on which a regular dot matrix pattern is printed in the central area to calibrate the distortion parameters of the camera under test. The distortion parameters include an intrinsic parameter matrix and a distortion coefficient vector. On the outer area of ​​the planar target plate, there are annular black stripes spaced at equal angles as angle markers.

[0012] Furthermore, the planar target plate is made of white translucent material, and LED light sources are arranged around the planar target plate to provide uniform illumination.

[0013] Furthermore, the cylindrical target unit adopts a cylindrical structure made of white translucent material or non-translucent material; when the cylindrical structure adopts white translucent material, black strips at equal angle intervals are pasted on the inner wall of the cylindrical structure as angle marks; when the cylindrical structure adopts non-translucent material, black strips at equal angle intervals are pasted on the outer wall of the cylindrical structure as angle marks; LED light sources are arranged around the cylindrical structure to provide uniform illumination for the cylindrical structure.

[0014] A method for testing the field of view of a camera, implemented using the aforementioned camera field of view testing device, includes the following steps: S1: Adjust the position and orientation of the camera under test so that the optical axis of the camera under test is perpendicular to the planar target unit and aligned with the center of the planar target unit. At the same time, ensure that all angle marks on the planar target unit and all angle marks on the cylindrical target unit are within the field of view of the camera under test. S2: Drive the planar target unit to rotate relative to the camera under test at least three different angular positions via a rotating mechanism; S3: At each angular position, images of the planar target unit and the cylindrical target unit are simultaneously acquired through the camera under test to obtain a calibration image set and a test image set. The calibration image set includes only images of the planar target unit, while the test image set includes images of both the planar target unit and the cylindrical target unit. S4: Extract feature points of the dot matrix pattern from the calibration image set, and use the camera calibration algorithm to calibrate the distortion parameters of the camera under test; S5: Using the distortion parameters of the camera under test, perform distortion correction on any image in the test image set based on the camera distortion model to obtain a distortion-free test image. S6: On the distortion-free test image, calculate the full field of view of the camera under test based on the angle markings with known angle values.

[0015] Furthermore, step S6 specifically includes the following steps: S61: Identify clear angular markers located at the edges of a distortion-free test image; S62: Determine the known angle values ​​corresponding to the two angle markers and their pixel coordinates in the distortion-free test image; S63: Calculate the full field of view of the camera under test based on the known angle values ​​and pixel coordinates of the two angle markers.

[0016] Furthermore, when the half field of view of the camera under test is 30°~40°, the first angle mark and the second angle mark are determined based on the annular equiangularly spaced black stripes in the distortion-free test image. When the half field of view of the camera under test is 50°~100°, the first angle mark and the second angle mark are determined based on the equally spaced black stripes in the distortion-free test image. The first and second angle markers are located at the two edges of the distortion-free test image; The known angle value corresponding to the first angle marker is m1, and the pixel coordinate is x1; The known angle value corresponding to the second angle marker is m2, and the pixel coordinate is x2; The pixel equivalent Δm is calculated using the following formula: Δm = (m2 - m1) / (x2 - x1); Based on the pixel equivalent Δm, the two half-field angles FOV1 and FOV2 of the camera under test are calculated using the following formula: FOV1=m1+Δm x 1_edge ; FOV2=m2+Δm x 2_edge ; Where, x 1_edge x represents the number of pixels from one edge of the distortion-free test image to the first marker. 2_edge This indicates the number of pixels from the other edge to the second marker in the distortion-free test image; Based on the two half-field-of-view angles FOV1 and FOV2 of the camera under test, the full field-of-view FOV of the camera under test is calculated using the following formula: FOV = FOV2 + FOV1.

[0017] Furthermore, step S2 includes three angular positions: a negative angular position, a zero-degree position, and a positive angular position.

[0018] Furthermore, the negative angle position is -5°, the zero angle position is 0°, and the positive angle position is +5°.

[0019] A computer device, comprising: At least one processor; and A memory that is communicatively connected to at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, which enables the at least one processor to perform the camera field of view testing method described above.

[0020] A non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the above-described camera field of view testing method.

[0021] Compared with the prior art, the present invention can achieve the following beneficial effects: 1. This invention first uses multi-angle calibration images to accurately solve for the distortion coefficient parameters of the vehicle-mounted camera, and then uses this as a basis to correct the distortion of the test images. This technical approach breaks through the premise of existing planar target methods that ignore distortion or assume that distortion is negligible, fundamentally eliminating the influence of radial distortion of large field-of-view vehicle-mounted cameras on the field-of-view measurement, and achieving a breakthrough in technical principles.

[0022] 2. This invention calculates the field of view on a distortion-free test image after distortion correction, effectively avoiding misjudgment of the field of view boundary and pixel equivalent calculation errors caused by edge pixel compression or stretching. For large field-of-view vehicle cameras, the testing accuracy of the field of view is significantly improved, meeting the requirements for high-precision calibration and quality control of vehicle cameras.

[0023] 3. Many vehicle vision algorithms (such as SLAM and object detection) require distortion correction of the original image before execution. The field of view measured by this invention is calculated based on distortion-free test images, thus better matching the effective perception range of vehicle cameras in actual ADAS systems and having higher engineering practical value.

[0024] 4. The entire testing process can be completed continuously in a short time. A rotating mechanism drives the planar target unit to rotate to multiple angles, simultaneously acquiring calibration and test images. Subsequently, distortion parameter calibration, correction, and field-of-view calculation are automatically completed. The entire process requires no manual intervention and can be seamlessly integrated with automated production lines, significantly improving testing efficiency while ensuring measurement accuracy. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the camera field of view testing device described in an embodiment of the present invention; Figure 2 A schematic diagram of the planar target unit described in the embodiment of the present invention; Figure 3 A schematic flowchart of the camera field of view testing method described in the embodiments of the present invention; Figure 4 A schematic diagram of the structure of the computer device described in the embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] This invention provides a camera field of view testing device and method, innovatively employing a calibration-correction-calculation approach to test the camera's field of view. More specifically, the distortion parameters of the vehicle-mounted camera are first calibrated using a calibration image, and these distortion parameters are then used to correct the distortion of the subsequent test image used for field of view calculation. This fundamentally eliminates the influence of distortion factors on the measurement results, thereby achieving high-precision calculation of the true value of the field of view on distortion-free test images.

[0031] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 and Figure 2As shown, the camera field of view testing device provided by the present invention includes a planar target unit 1, a cylindrical target unit 2, and a rotating mechanism 3. The planar target unit 1 provides calibration images and test images for the camera under test 4. The calibration images are used to calibrate the distortion parameters of the camera under test 4, and the test images are used to measure the field of view of the camera under test 4. The cylindrical target unit 2 only provides test images for the camera under test 4, used to measure the field of view of the camera under test 4. The rotating mechanism 3 is connected to the planar target unit 1 and is used to drive the planar target unit 1 to rotate relative to the camera under test 4 at least three different angular positions, providing calibration images from different viewing angles to the camera under test 4, thereby achieving subsequent distortion parameter calibration.

[0033] The planar target unit 1 includes a planar target plate 1-1. A regular dot matrix pattern 1-2, such as a common checkerboard pattern or a circular dot array pattern, is printed in the central area of ​​the planar target plate 1-1. The regular dot matrix pattern is used to calibrate the image, providing feature points and enabling the calibration of distortion parameters, including the intrinsic parameter matrix and distortion coefficient vector. Annular, equally spaced black stripes 1-3 are arranged on the outer area of ​​the planar target plate 1-1. These stripes serve as angular markers for subsequent viewing angle testing. A black strip can be attached at 10° intervals. The planar target plate 1-1 is made of a white translucent material (such as white diffuse-reflective plastic), and LED light sources 1-4 are arranged around it to provide uniform illumination and ensure image contrast.

[0034] The cylindrical target unit 2 has a cylindrical structure. The cylinder itself is made of white translucent material. Equally spaced black strips 2-1 are affixed to the inner wall of the cylinder, serving as angular markers for subsequent viewing angle testing. A black strip can be affixed every 10°. Alternatively, the cylinder can be made of a non-translucent material, in which case the equally spaced black strips 2-1 are affixed to the outer wall. The equally spaced black strips 2-1 can be replaced with a specific pattern (such as concentric rings or radial line segments) printed on a planar chart, distributed at known angles from the center outwards. LED light sources 2-2 are arranged around the cylindrical structure to provide uniform illumination.

[0035] In this invention, the angle marks on the planar target plate 1-1 and the angle marks on the cylinder correspond to real-world angle values, which are known quantities and serve as angle references.

[0036] The output shaft of the rotating mechanism 3 is connected to the planar target plate 1-1 and is used to drive the planar target plate 1-1 to rotate with high precision. The rotation range is preferably ±5°.

[0037] like Figure 3As shown, the camera field of view testing method provided by the present invention is implemented using the above-mentioned camera field of view testing device, and includes the following steps: S1: Adjust the position and orientation of the camera under test so that the optical axis of the camera under test is perpendicular to the planar target unit and aligned with the center of the planar target unit. At the same time, ensure that all angle marks on the planar target unit and all angle marks on the cylindrical target unit are within the field of view of the camera under test.

[0038] Fix the camera under test onto the test fixture, and adjust the position and orientation of the camera under test using the test fixture so that the optical axis of the camera under test is perpendicular to the planar target unit and aligned with the center of the planar target unit, and ensure that the camera under test can completely capture the annular equidistant black stripes on the planar target unit and the equidistant black stripes on the cylindrical target unit.

[0039] S2: Drive the planar target unit to rotate at least three different angular positions relative to the camera under test via a rotating mechanism.

[0040] Taking three angular positions as an example, the same logic applies to more angles. The three angular positions are the negative angle position, the zero-degree position, and the positive angle position. Preferably, the negative angle position is -5°, the zero-degree position is 0°, and the positive angle position is +5°.

[0041] S3: At each angular position, images of the planar target unit and the cylindrical target unit are simultaneously acquired through the camera under test to obtain a calibration image set and a test image set. The calibration image set includes only images of the planar target unit, while the test image set includes images of both the planar target unit and the cylindrical target unit.

[0042] Images captured by the planar target unit serve as both calibration images for calibrating distortion parameters and test images for testing the field of view, while images captured by the cylindrical target unit are used solely as test images. When images from the planar target unit are used as test images, they are used to test cameras with a small field of view (half-field of view between 30° and 40°). When images from the cylindrical target unit are used as test images, they are used to test cameras with a large field of view (half-field of view between 50° and 100°).

[0043] S4: Extract feature points of the dot matrix pattern from the calibration image set, and use the camera calibration algorithm to calibrate the intrinsic parameter matrix and distortion coefficient vector of the camera under test.

[0044] Whether the image of a planar target unit or the image of a cylindrical target unit is used as the test image, the distortion parameters are calibrated through the calibration image.

[0045] The camera calibration algorithm can adopt a mature camera calibration algorithm, which utilizes the correspondence between the feature point coordinates extracted from multiple angles and the known three-dimensional world coordinates to calculate the intrinsic parameter matrix (including parameters such as focal length and principal point) and distortion coefficient vector of the camera under test.

[0046] The distortion coefficient vector includes at least radial distortion coefficients k1, k2, k3, etc., and may also include tangential distortion coefficients p1, p2 as needed.

[0047] S5: Using the intrinsic parameter matrix and distortion coefficient vector of the camera under test, distortion correction is performed on any image in the test image set based on the camera distortion model to obtain a distortion-free test image.

[0048] Using the calibrated intrinsic parameter matrix and distortion coefficient vector, distortion correction is performed on any image in the test image set. The correction process is based on the same distortion model (e.g., the Brown-Conrady model). Through mapping transformation, pixels in the test image that have been offset due to lens distortion are reprojected to their proper positions under the ideal pinhole camera model, thereby generating a distortion-free test image with corrected geometric distortion.

[0049] S6: On the distortion-free test image, calculate the full field of view of the camera under test based on the angle markings with known angle values.

[0050] The specific steps for calculating the full field of view of the camera under test are as follows: S61: Identify clear angular markers located at the edges of a distortion-free test image.

[0051] When the camera under test is a small field of view camera (half field of view between 30° and 40°), the image of the planar target unit is used as the distortion-free test image after distortion correction. The positions of the first angle mark and the second angle mark are determined based on the annular equiangularly spaced black stripes in the distortion-free test image. At this time, the first angle mark and the second angle mark are black stripes that are still clearly distinguishable at the two edges of the image.

[0052] When testing a camera with a large field of view (half field of view between 50° and 100°), the image of the cylindrical target unit is used as the distortion-free test image after distortion correction. The positions of the first angle mark and the second angle mark are determined based on the equally spaced black stripes in the distortion-free test image. At this time, the first angle mark and the second angle mark are black stripes that are still clearly distinguishable at the two edges of the image, where the equally spaced black stripes are located.

[0053] S62: Determine the known angle values ​​corresponding to the two angle markers and their pixel coordinates in the distortion-free test image.

[0054] The known angle value corresponding to the first angle marker is m1, and the pixel coordinate is x1.

[0055] The known angle value corresponding to the second angle marker is m2, and the pixel coordinate is x2.

[0056] S63: Calculate the full field of view of the camera under test based on the known angle values ​​and pixel coordinates of the two angle markers.

[0057] First, calculate the pixel equivalent Δm based on m1, x1, m2, and x2. The calculation formula is as follows: Δm=(m2-m1) / (x2-x1).

[0058] Next, based on the pixel equivalent Δm, calculate the two half-field-of-view angles FOV1 and FOV2 of the camera under test. FOV1 and FOV2 are the angles from the optical axis of the camera under test to the two side field-of-view boundaries, respectively. The formulas for calculating FOV1 and FOV2 are as follows: FOV1=m1+Δm x 1_edge ; FOV2=m2+Δm x 2_edge ; Where, x 1_edge x represents the number of pixels from one edge of the distortion-free test image to the first marker. 2_edge This represents the number of pixels from the other edge to the second marker in the distortion-free test image.

[0059] Finally, the full field of view (FOV) of the camera under test is calculated based on the two half-field of view angles, FOV1 and FOV2. The calculation formula is as follows: FOV = FOV2 + FOV1.

[0060] This invention preferentially selects images acquired at a 0° position as test images. At 0°, the optical axis of the camera under test is basically aligned with the axis of the cylindrical target unit, and the black bars are symmetrically distributed in the image. The outermost visible bar is closer to the edge of the field of view, making it easier to accurately calculate the field of view boundary. Furthermore, the center of the field of view of the camera under test is basically coincident with the center of the image, making the calculation of pixel equivalents simpler and introducing less error. At ±5° positions, the black bars on one side of the image are closer to the edge, while the black bars on the other side may be missing or blurred, and the black bars on both sides are asymmetrical, resulting in incomplete imaging or reduced clarity of the black bars on that side, making it difficult to accurately identify angle marks, and thus affecting the accuracy of the field of view test.

[0061] Accordingly, according to embodiments of the present invention, the present invention also provides a computer device and a readable storage medium.

[0062] Figure 4 This is a schematic diagram of the structure of a computer device 12 provided in an embodiment of the present invention. Figure 4 A block diagram of an exemplary computer device 12 suitable for implementing embodiments of the present invention is shown. Figure 4 The computer device 12 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0063] like Figure 4 As shown, computer device 12 is represented in the form of a general-purpose computing device. Computer device 12 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0064] The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0065] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0066] Computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0067] System memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. Computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media (…). Figure 4 Not shown; usually referred to as a "hard drive"). Although Figure 4Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. Memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0068] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0069] Computer device 12 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with computer device 12, and / or with any device that enables computer device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed via input / output (I / O) interface 22. Furthermore, computer device 12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 20. As shown, network adapter 20 communicates with other modules of computer device 12 via bus 18. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0070] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the camera field of view testing method provided in the embodiments of the present invention.

[0071] This invention also provides a non-transitory computer-readable storage medium storing computer instructions, on which a computer program is stored, wherein the program, when executed by a processor, is the camera field of view testing method provided in all embodiments of this application.

[0072] The computer storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0073] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0074] The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof. The computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0075] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0076] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A camera field of view testing device, characterized in that, include: The planar target unit is used to provide calibration images and test images for the camera under test. The calibration image is used to calibrate the distortion parameters of the camera under test, and the test image is used to measure the field of view of the camera under test. Angle marks with known angle values ​​are set on the planar target unit. A cylindrical target unit is used to provide test images for the camera under test. The test images are used to measure the field of view of the camera under test. Angle marks with known angle values ​​are set on the cylindrical target unit. A rotating mechanism, connected to a planar target unit, is used to drive the planar target unit to rotate relative to the camera under test at least three different angular positions.

2. The camera field of view testing device according to claim 1, characterized in that, The planar target unit includes a planar target plate with a regular dot matrix pattern printed in the central area of ​​the planar target plate to calibrate the distortion parameters of the camera under test. The distortion parameters include an intrinsic parameter matrix and a distortion coefficient vector. A ring-shaped black stripe with equal angular intervals is arranged in the outer area of ​​the planar target plate as an angle marker.

3. The camera field of view testing device according to claim 2, characterized in that, The planar target board is made of white translucent material, and LED light sources are arranged around the planar target board to provide uniform illumination.

4. The camera field of view testing device according to claim 1, characterized in that, The cylindrical target unit is a cylindrical structure made of white translucent or non-translucent material. When the cylindrical structure is made of white translucent material, black strips at equal angles are pasted on the inner wall of the cylindrical structure as angle marks. When the cylindrical structure is made of non-translucent material, black strips at equal angles are pasted on the outer wall of the cylindrical structure as angle marks. LED light sources are arranged around the cylindrical structure to provide uniform illumination for the cylindrical structure.

5. A method for testing the field of view of a camera, implemented using the camera field of view testing device according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1: Adjust the position and orientation of the camera under test so that the optical axis of the camera under test is perpendicular to the planar target unit and aligned with the center of the planar target unit. At the same time, ensure that all angle marks on the planar target unit and all angle marks on the cylindrical target unit are within the field of view of the camera under test. S2: Drive the planar target unit to rotate relative to the camera under test at least three different angular positions via a rotating mechanism; S3: At each angular position, images of the planar target unit and the cylindrical target unit are simultaneously acquired through the camera under test to obtain a calibration image set and a test image set. The calibration image set includes only images of the planar target unit, while the test image set includes images of both the planar target unit and the cylindrical target unit. S4: Extract feature points of the dot matrix pattern from the calibration image set, and use the camera calibration algorithm to calibrate the distortion parameters of the camera under test; S5: Using the distortion parameters of the camera under test, perform distortion correction on any image in the test image set based on the camera distortion model to obtain a distortion-free test image. S6: On the distortion-free test image, calculate the full field of view of the camera under test based on the angle markings with known angle values.

6. The camera field of view testing method according to claim 5, characterized in that, Step S6 specifically includes the following steps: S61: Identify clear angular markers located at the edges of a distortion-free test image; S62: Determine the known angle values ​​corresponding to the two angle markers and their pixel coordinates in the distortion-free test image; S63: Calculate the full field of view of the camera under test based on the known angle values ​​and pixel coordinates of the two angle markers.

7. The camera field of view testing method according to claim 6, characterized in that, When the half field of view of the camera under test is 30°~40°, the first angle mark and the second angle mark are determined based on the annular equiangularly spaced black stripes in the distortion-free test image. When the half field of view of the camera under test is 50°~100°, the first angle mark and the second angle mark are determined based on the equally spaced black stripes in the distortion-free test image. The first and second angle markers are located at the two edges of the distortion-free test image; The known angle value corresponding to the first angle marker is m1, and the pixel coordinate is x1; The known angle value corresponding to the second angle marker is m2, and the pixel coordinate is x2; The pixel equivalent Δm is calculated using the following formula: Δm = (m2 - m1) / (x2 - x1); Based on the pixel equivalent Δm, the two half-field angles FOV1 and FOV2 of the camera under test are calculated using the following formula: FOV1=m1+Δm x 1_edge ; FOV2=m2+Δm x 2_edge ; Where, x 1_edge x represents the number of pixels from one edge of the distortion-free test image to the first marker. 2_edge This indicates the number of pixels from the other edge to the second marker in the distortion-free test image; Based on the two half-field-of-view angles FOV1 and FOV2 of the camera under test, the full field-of-view FOV of the camera under test is calculated using the following formula: FOV = FOV2 + FOV1.

8. The camera field of view testing method according to any one of claims 5 to 7, characterized in that, Step S2 includes three angular positions: a negative angular position, a zero-degree position, and a positive angular position.

9. The camera field of view testing method according to claim 8, characterized in that, The negative angle position is -5°, the zero angle position is 0°, and the positive angle position is +5°.

10. A computer device, characterized in that, include: At least one processor; as well as A memory that is communicatively connected to at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, causes the at least one processor to perform the camera field of view testing method according to any one of claims 5 to 9.

11. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to execute the camera field of view testing method according to any one of claims 5 to 9.

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