Calibration board
By setting multiple calibration rows and different number of calibration circle holes on the calibration plate, and combining identifiers to provide position coordinates in the X, Y and Z directions, the problem of limited identification accuracy of calibration plates in the prior art is solved, and the improvement is achieved Wide applicability and efficient calibration.
Patent Information
- Application Number
- CN202420080025.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-01-12
AI Technical Summary
In the prior art, the circular array calibration plate has limited recognition accuracy in various scenarios and cannot meet the higher calibration plate applicability requirements.
A calibration plate is designed, with multiple calibration rows arranged on the calibration surface. Each calibration row includes multiple calibration circle holes. The number of calibration circle holes in adjacent calibration rows is different, and different calibration rows are set on the same number of calibration rows. Identifiers, which provide position coordinates in the X, Y and Z directions through these features, improve calibration accuracy and efficiency.
It realizes high-precision calibration in various scenarios, expands the scope of application of the calibration plate, improves calibration efficiency and simplicity of operation, reduces processing costs, and is suitable for algorithm calibration of dual cameras and multi-camera.
Smart Images
Figure CN222167631U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of image processing, and more specifically to a calibration plate. Background Art
[0002] Camera calibration is a basic part of machine vision applications such as visual measurement and 3D reconstruction. The accuracy and precision of the calibration results directly determine whether the visual system can work properly. Camera calibration refers to the process of using a camera system to capture an image of a calibration plate, and using the 3D coordinates of known feature points in the calibration plate and the corresponding image coordinates on the image to calculate the camera parameters.
[0003] In the prior art, the calibration plates used in the collection of camera calibration data are generally checkerboards and circular arrays. Among them, the circular array calibration plate has high requirements for the recognition accuracy of the center of the circle during use, resulting in limited application scenarios and failure to obtain better recognition accuracy of the calibration plate under various conditions.
[0004] Therefore, how to improve the applicability of the calibration plate in various scenarios has become a technical problem that needs to be urgently solved by technical personnel in this field. Utility Model Content
[0005] In view of this, an object of the present invention is to provide a calibration plate to improve the applicability of the calibration plate in various scenarios.
[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0007] A calibration plate, comprising:
[0008] A calibration surface is provided with a plurality of calibration rows, each of the calibration rows comprises a plurality of calibration circular holes, and the numbers of calibration circular holes in adjacent calibration rows are different, and the calibration rows with the same number of calibration circular holes are provided with different identifiers.
[0009] Optionally, in the above-mentioned calibration plate, the calibration circular hole is an inverted cone, and the calibration circular hole has a small diameter end and a large diameter end, the small diameter end of the calibration circular hole is located on the calibration surface, and the large diameter end of the calibration circular hole is located on the fixed surface opposite to the calibration surface.
[0010] Optionally, in the above calibration plate, a plurality of fixed blind holes for fixing the scanned object are arranged on the fixed surface.
[0011] Optionally, in the above calibration plate, the calibration plate is a rectangular plate, and the fixing blind holes are four threaded holes, each of which is located at the four corners of the fixing surface.
[0012] Optionally, in the above calibration plate, the identifier includes different numbers of identification holes arranged at the ends of the calibration row.
[0013] Optionally, in the calibration plate, the inner surface of the calibration circular hole is a smooth surface to ensure the sharpness of the circular hole edge of the calibration circular hole on the calibration surface.
[0014] Optionally, in the above calibration plate, the calibration plate is made of ceramic material or metal material.
[0015] Optionally, in the above calibration plate, the surface of the calibration plate is processed by a matte process.
[0016] Optionally, in the above calibration plate, the calibration circular holes in adjacent calibration rows are arranged in a staggered manner.
[0017] The calibration plate provided by the utility model is provided with a plurality of calibration rows on the calibration surface, each calibration row includes a plurality of calibration circular holes, and the number of calibration circular holes of adjacent calibration rows is different, and different identifiers are provided in the calibration rows with the same number of calibration circular holes. When the image features on the calibration plate are collected by the camera to be calibrated, the calibration circular holes set in each calibration row can provide the algorithm with X-direction position coordinates, and the position of the calibration row where the calibration point is located can be determined by the different numbers of calibration circular holes in adjacent calibration rows, thereby providing the algorithm with Y-direction position coordinates; if the camera to be calibrated collects the image features on the calibration plate and includes a plurality of calibration rows with the same number of calibration circular holes, the position of the calibration row where the calibration point is located can be determined by different identifiers, thereby providing the algorithm with Y-direction position coordinates. The depth of the calibration circular holes can provide the algorithm with Z-direction position coordinates. Of course, the algorithm can also be provided with Y-direction position coordinates through the calibration holes set in each calibration row, and the algorithm can be provided with X-direction position coordinates through different numbers of calibration holes and different identifiers set in adjacent calibration rows, so that the camera to be calibrated can simultaneously obtain high-precision real data in the three directions of X, Y and Z when collecting image data of the above calibration plate.
[0018] Compared with the prior art, the calibration plate provided by the utility model sets different numbers of calibration holes in adjacent calibration rows, so as to quickly locate the position of the calibration row where the calibration point is located, and when it contains multiple calibration rows with the same number of calibration holes, the position of the calibration row where the calibration point is located can be determined by different identifiers, so as to provide the Y-direction position coordinates for the algorithm, and at the same time, the X-direction position coordinates are provided to the algorithm through the calibration holes in each calibration row, and the Z-direction position coordinates are provided to the algorithm through the depth of the calibration holes, so that the calibration plate has three-dimensional calibration parameters, a wider range of use, higher calibration efficiency, simple structure, easy operation, lower processing cost, can be used for algorithm calibration of dual cameras and multiple cameras, and the applicability of the calibration plate in various scenarios is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0020] Figure 1 The structure of the calibration plate provided in the embodiment of the utility model is shown in FIG. Figure 1 ;
[0021] Figure 2 The structure of the calibration plate provided in the embodiment of the utility model is shown in FIG. Figure 2 .
[0022] Among them, 100 is a calibration plate, 101 is a calibration surface, 102 is a calibration row, 103 is a calibration circular hole, 1031 is a small diameter end, 1032 is a large diameter end, 104 is an identifier, 1041 is an identification hole, 105 is a fixing surface, and 106 is a fixing blind hole. DETAILED DESCRIPTION
[0023] The core of the utility model is to provide a calibration plate to improve the applicability of the calibration plate in various scenarios.
[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of this application.
[0025] like Figure 1As shown, the embodiment of the utility model discloses a calibration plate, including a calibration surface 101. It should be noted that in the prior art, the calibration plates used in the collection of camera calibration data are generally checkerboards and circular arrays. Among them, the circular array calibration plate has a high requirement for the recognition accuracy of the center of the circle during use, resulting in limited application scenarios and failure to obtain better recognition accuracy of the calibration plate under various conditions. The calibration plate 100 disclosed in the embodiment of the utility model sets different numbers of calibration holes 103 in adjacent calibration rows 102, so as to quickly locate the position of the calibration row 102 where the calibration point is located, and when it contains multiple calibration rows 102 with the same number of calibration holes 103, the position of the calibration row 102 where the calibration point is located can be determined by different identifiers 104, so as to provide the Y-direction position coordinate for the algorithm, and at the same time, the X-direction position coordinate is provided to the algorithm through the calibration holes 103 of each calibration row 102, and the Z-direction position coordinate is provided to the algorithm through the depth of the calibration holes 103, so that the calibration plate 100 has three-dimensional calibration parameters, a wider range of use, higher calibration efficiency, simple structure, convenient operation, lower processing cost, and can be used for algorithm calibration of dual cameras and multiple cameras, thereby improving the applicability of the calibration plate 100 in various scenarios.
[0026] Among them, Figure 1 As shown, a plurality of calibration rows 102 are arranged on the calibration surface 101, each calibration row 102 includes a plurality of calibration holes 103, and the number of calibration holes 103 of adjacent calibration rows 102 is different, and the calibration holes of adjacent calibration rows are arranged in a staggered manner, and different identifiers 104 are arranged in the calibration rows 102 with the same number of calibration holes 103. Specifically, for ease of understanding, as Figure 1 and Figure 2 As shown, two opposite sides of the calibration plate 100 are defined as a first side and a second side, respectively, and the calibration surface 101 is set on the first side, and the second side of the calibration plate 100 is a fixed surface 105. At the same time, the calibration plate 100 adopts a rectangular plate, the length direction of the calibration plate 100 is defined as the X direction, and the width direction of the calibration plate 100 is defined as the Y direction. There are multiple calibration rows 102, which can be 3, 4 or 5, etc., and the number of calibration circular holes 103 set in each calibration row 102 is multiple, which can be 3, 4 or 5, etc., and the specific number can be determined according to the data accuracy requirements.
[0027] When the calibration camera is used to collect image features on the calibration plate 100, the position of the calibration point in the X direction can be determined by the calibration circular holes 103 set in each calibration row 102, so as to provide the algorithm with the X direction position coordinates, and the position of the calibration row 102 where the calibration point is located can be quickly determined by the different numbers of calibration circular holes 103 in adjacent calibration rows 102. At the same time, the calibration circular holes 103 in adjacent calibration rows 102 are arranged in a staggered manner, which can improve the efficiency of determining the position of the calibration row 102 where the calibration point is located, thereby determining the position of the calibration point in the Y direction, so as to provide the algorithm with the Y direction position coordinates; if the calibration camera to be calibrated contains multiple calibration rows 102 with the same number of calibration circular holes 103 when collecting image features on the calibration plate 100, the position of the calibration row 102 where the calibration point is located can be determined by different identifiers 104, so as to provide the algorithm with the Y direction position coordinates. And the Z direction position coordinates can be provided to the algorithm by the depth of the calibration circular holes 103. Then, when the camera to be calibrated collects image data of the calibration plate 100, high-precision real data in the three directions of X, Y and Z can be obtained simultaneously. Of course, the calibration circular holes 103 set in each calibration row 102 can also be used to provide the algorithm with Y-direction position coordinates, and the different numbers of calibration circular holes 103 and different identifiers 104 set in adjacent calibration rows 102 can be used to provide the algorithm with X-direction position coordinates. In this case, it is only necessary to define the width direction of the calibration plate 100 as the X direction and the length direction of the calibration plate 100 as the Y direction.
[0028] like Figure 1 As shown, for ease of understanding, the calibration rows 102 on the calibration surface 101 are defined as the first calibration row and the second calibration row, respectively. In a specific embodiment, the number of calibration circular holes on the first calibration row is 6, the number of calibration circular holes on the second calibration row is 5, the number of first calibration rows is 3, the number of second calibration rows is 2, and the first calibration row and the second calibration row are alternately arranged in sequence along the width direction of the calibration plate 100. At the same time, different identifiers 104 are respectively arranged on the three first calibration rows to distinguish the specific positions of the calibration points in the first calibration rows, and similarly, different identifiers 104 are arranged on the two second calibration rows to distinguish the specific positions of the calibration points in the second calibration rows, so as to determine the position of the calibration points in the Y direction, so as to provide the Y direction position coordinates for the algorithm.
[0029] Further, the identifier 104 includes different numbers of identification holes 1041, and the identification holes 1041 are arranged at the ends of the marking rows 102. In this embodiment, the number of identification holes 1041 can be 0, 1, 2, 3, etc. Specifically, at the left end of the three first marking rows ( Figure 1 1, 2 and 0 marking holes 1041 are arranged from top to bottom, respectively, and at the left end of the 2 second marking rows ( Figure 1In the example of FIG. 1041 , 0 and 1 identification holes 1041 are set from top to bottom, respectively. The identification holes 1041 can be used to distinguish the specific calibration row 102 where the calibration point is located, thereby providing the algorithm with the Y-direction position coordinate. At the same time, by setting different numbers of identification holes 1041, the X-direction and Y-direction of the camera to be calibrated can be distinguished during multi-camera calibration, thereby confirming the correspondence between the multiple cameras. For example, for two cameras to be calibrated (camera A and camera B), the correspondence between the two cameras to be calibrated can be determined by camera A being close to the identification hole 1041 and camera B being far away from the identification hole 1041, that is, the identification hole 1041 can be used as a reference reference point, thereby making the calibration plate 100 usable for algorithm calibration of dual cameras and multiple cameras, thereby improving the applicability of the calibration plate 100 in various scenarios. It should be noted that 0 identification holes 1041 refers to the case where no identification holes 1041 are set.
[0030] The calibration plate 100 disclosed in the embodiment of the utility model is provided with a plurality of calibration rows 102 on the calibration surface 101, each calibration row 102 includes a plurality of calibration circular holes 103, and the number of calibration circular holes 103 of adjacent calibration rows 102 is different, and different identifiers 104 are provided in the calibration rows 102 with the same number of calibration circular holes 103. When the image features on the calibration plate 100 are collected by the camera to be calibrated, the calibration circular holes 103 provided in each calibration row 102 can provide the algorithm with the X-direction position coordinates, and the position of the calibration row 102 where the calibration point is located can be determined by the number of different calibration circular holes 103 of adjacent calibration rows 102, thereby providing the algorithm with the Y-direction position coordinates; if the camera to be calibrated contains a plurality of calibration rows 102 with the same number of calibration circular holes 103 when collecting the image features on the calibration plate 100, the position of the calibration row 102 where the calibration point is located can be determined by different identifiers 104, thereby providing the algorithm with the Y-direction position coordinates. The Z-direction position coordinates are provided to the algorithm by the depth of the calibration holes 103. Of course, the Y-direction position coordinates can also be provided to the algorithm by the calibration holes 103 set in each calibration row 102, and the X-direction position coordinates can be provided to the algorithm by the different numbers of calibration holes 103 in adjacent calibration rows 102 and the different identifiers 104 set, so that when the camera to be calibrated collects the image data of the calibration plate 100, high-precision real data in the three directions of X, Y and Z can be obtained simultaneously.
[0031] Compared with the prior art, the calibration plate 100 disclosed in the embodiment of the utility model sets different numbers of calibration holes 103 in adjacent calibration rows 102, so as to quickly locate the position of the calibration row 102 where the calibration point is located, and when a plurality of calibration rows 102 are included with the same number of calibration holes 103, the position of the calibration row 102 where the calibration point is located can be determined by different identifiers 104, so as to provide the algorithm with the Y-direction position coordinate, and at the same time, the calibration holes 103 in each calibration row 102 are used to provide the algorithm with the X-direction position coordinate, and the depth of the calibration holes 103 is used to provide the algorithm with the Z-direction position coordinate, so that the calibration plate 100 has three-dimensional calibration parameters, a wider range of use, higher calibration efficiency, simple structure, convenient operation, lower processing cost, and can be used for algorithm calibration of dual cameras and multiple cameras, thereby improving the applicability of the calibration plate 100 in various scenarios.
[0032] Furthermore, if Figure 1 and Figure 2 As shown, in a specific embodiment, the calibration hole 103 is an inverted cone, and the calibration hole 103 has a small diameter end 1031 and a large diameter end 1032. The small diameter end 1031 of the calibration hole 103 is located on the calibration surface 101, that is, the first side of the calibration plate 100, and the large diameter end 1032 of the calibration hole 103 is located on the fixed surface 105 opposite to the calibration surface 101, that is, the second side of the calibration plate 100. By using the circular hole conical processing on the second side of the calibration plate 100, the inner surface of the calibration hole 103 is a smooth surface to ensure the sharpness of the circular hole edge of the calibration hole 103 on the calibration surface 101, thereby avoiding noise interference on the inner wall of the calibration hole 103, which affects the accuracy of the algorithm. In addition, as Figure 2 As shown, a plurality of fixed blind holes 106 for fixing the scanned object are provided on the fixed surface 105. The fixed blind holes 106 are four threaded holes, each of which is located at the four corners of the fixed surface 105, and can fix the scanned object under the camera to be calibrated when the camera to be calibrated moves.
[0033] Furthermore, the material of the calibration plate 100 can be a ceramic material or a metal material with high strength and good wear resistance, and the surface of the calibration plate 100 is treated by a matte process to avoid the phenomenon of light transmission and reflection of the calibration plate 100, so as to better identify the information of the calibration points of the calibration plate 100, thereby achieving higher calibration accuracy and measurement accuracy. Of course, the material of the calibration plate 100 is not limited to the two materials disclosed in the above embodiments, and optical glass material can also be used, which can be selected according to the position of the light source.
[0034] The terms "first" and "second" in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may include steps or units that are not listed.
[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A calibration plate, characterized in that: include: A calibration surface (101), wherein a plurality of calibration rows (102) are arranged on the calibration surface (101), each of the calibration rows (102) comprises a plurality of calibration circular holes (103), and the numbers of the calibration circular holes (103) in adjacent calibration rows (102) are different, and the calibration rows (102) with the same number of the calibration circular holes (103) are provided with different identifiers (104).
2. The calibration plate according to claim 1, characterized in that: The calibration circular hole (103) is in an inverted cone shape, and has a small diameter end (1031) and a large diameter end (1032); the small diameter end (1031) of the calibration circular hole (103) is located on the calibration surface (101), and the large diameter end (1032) of the calibration circular hole (103) is located on a fixed surface (105) opposite to the calibration surface (101).
3. The calibration plate according to claim 2, characterized in that: The fixing surface (105) is provided with a plurality of fixing blind holes (106) for fixing the scanning object.
4. The calibration plate according to claim 3, characterized in that: The calibration plate (100) is a rectangular plate, and the fixing blind holes (106) are four threaded holes, each of which is located at the four corners of the fixing surface (105).
5. The calibration plate according to claim 1, characterized in that: The identifier (104) includes different numbers of identification holes (1041) arranged at the end of the calibration row (102).
6. The calibration plate according to claim 1, characterized in that: The inner surface of the calibration circular hole (103) is a smooth surface to ensure the sharpness of the circular hole edge of the calibration circular hole (103) on the calibration surface (101).
7. The calibration plate according to claim 1, characterized in that: The calibration plate (100) is made of ceramic material or metal material.
8. The calibration plate according to claim 1, characterized in that: The surface of the calibration plate (100) is processed by a matte process.
9. The calibration plate according to claim 1, characterized in that: The calibration circular holes (103) of adjacent calibration rows (102) are arranged in a staggered manner.