Checkerboard corner point detection method and device

A grid corner point and point detection technology is applied in the field of checkerboard grid corner point detection method and device, which can solve the problems of poor applicability of calibration environment and high cost of setting up calibration environment, so as to improve robustness, improve calibration accuracy, and improve The effect of detection accuracy

Active Publication Date: 2017-06-13
X CHIP MICROELECTRONICS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The quality of the corner point extraction of the checkerboard directly determines the calibration quality of the camera. The commonly used corner point extraction algorithms are generally based on the gradient characteristics of the corner points to select the corner points. There are strict requirements, and it can only be carried out in a field of view with a single background. The applicability of the calibration environment is not strong, and the construction cost of the calibration environment is high.

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  • Checkerboard corner point detection method and device
  • Checkerboard corner point detection method and device
  • Checkerboard corner point detection method and device

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Experimental program
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Effect test

Embodiment 1

[0061] Figure 1AIt is a flow chart of the checkerboard corner detection method provided by Embodiment 1 of the present invention. This embodiment is applicable to the detection of checkerboard corners in any field of view background. device, the device may be implemented in the form of software and / or hardware, and the method specifically includes:

[0062] S110. Acquire a grayscale image of the calibration scene, and determine candidate corner points according to the grayscale image.

[0063] Wherein, the calibration scene refers to the background where the checkerboard is located. Exemplarily, the calibration scene may be a table with a checkerboard, a book with a checkerboard, or a scene including other background objects with a checkerboard. Take image capture of the calibration scene. If the acquired image is a color image, you need to convert the color image to a grayscale image.

[0064] Pixels of a grayscale image have 256 grayscales from black to white, wherein a co...

Embodiment 2

[0094] Figure 2A It is a flow chart of the checkerboard corner detection method provided in Embodiment 2 of the present invention. On the basis of the above embodiments, a method for growing corners of candidate corners according to the corner growth algorithm is further provided. Correspondingly, the method Specifically include:

[0095] S210. Acquire a grayscale image of the calibration scene, and determine candidate corner points according to the grayscale image.

[0096] S220. Determine the sub-pixel edge direction of the candidate corner point.

[0097] Wherein, an edge refers to a collection of pixel points whose pixel gray value changes sharply only in one direction, for example, in a checkerboard, it may be a pixel point whose pixel gray value changes sharply only in the horizontal or vertical direction The set of , the edge direction refers to the direction perpendicular to the edge gray gradient. Wherein, the sub-pixel edge direction refers to the sub-pixel edge ...

Embodiment 3

[0114] Fig. 3 is a flow chart of the checkerboard corner detection method provided by the third embodiment of the present invention. On the basis of the above embodiment, a method for growing the corners of the initial frame through the prediction error algorithm is further provided. Correspondingly, the The methods specifically include:

[0115] S310. Acquire a grayscale image of the calibration scene, and determine candidate corner points according to the grayscale image.

[0116] S320. Determine the sub-pixel edge direction of the candidate corner point.

[0117] S330. Perform corner growth on corner points according to the sub-pixel edge direction and checkerboard size, and determine an initial frame for candidate corner growth.

[0118] S340. Determine a line distance between known corner points having a common edge among the known corner points.

[0119] Wherein, if there are two known corner points on a certain edge, the edge is determined as the common edge of the ab...

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Abstract

The embodiment of the invention discloses a checkerboard corner point detection method and device. The method includes the steps that a gray image of a calibrated scene is obtained, and candidate corner points are determined according to the gray image; corner point growth is conducted on the candidate corner points through the corner point growth algorithm, the candidate corner points are screened according to corner point growth results, and checkerboard corner points are determined; sub-pixel positions of the checkerboard corner points are determined according to the checkerboard corner points. The method and device solve the problem that symmetric background corner points can not be eliminated, precise corner point detection can be conducted under a complex calibration background, and the robustness of corner point detection is improved.

Description

technical field [0001] Embodiments of the present invention relate to image processing technologies, and in particular to a checkerboard corner detection method and device. Background technique [0002] Machine vision is playing an increasing role in automatic assembly, 3D modeling, automatic navigation, and robotics. When the camera quantitatively models the scene by obtaining visual information in the space, the physical parameters and geometric parameters of the camera are needed, and the physical parameters and geometric parameters of the camera are generally determined by camera calibration. [0003] At present, the camera calibration often adopts the checkerboard calibration method, which has the advantages of easy control of feature point accuracy, simple and easy extraction, etc. The quality of the corner point extraction of the checkerboard directly determines the calibration quality of the camera. The commonly used corner point extraction algorithms are generally ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06T7/80
Inventor 童飞
Owner X CHIP MICROELECTRONICS TECH CO LTD
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