Camera calibration board, calibration method and camera

Abstract

The invention relates to a camera calibration board, a calibration method and a camera. According to the invention, circular mark points with different sizes are adopted, and detection is carried outby taking a reference dot as a reference. The calibration method comprises the following steps: carrying out edge extraction on a calibration plate image collected by a camera to obtain an edge contour of each dot; Performing ellipse fitting on the edge contour of each dot to obtain a fitting ellipse corresponding to each dot; Positioning a reference ellipse according to the size and position relationship between the fitted ellipses; Taking the reference ellipse as a seed point, finishing the sorting of all mark points, and obtaining image coordinates and world coordinates which are in one-to-one correspondence; And completing calibration calculation of camera parameters by using the image coordinates and the world coordinates. In the calibration process, the calibration plate is placed flexibly, the calibration of the camera can be completed only by ensuring that the reference round points are located in the visual field and providing the point spacing and without providing the row and column number of the mark points of the calibration plate, and the robustness and the precision of calibration are effectively improved.

Description

technical field [0001] The invention relates to the field of camera calibration, more specifically, to a camera calibration board, a calibration method and a camera. Background technique [0002] In machine vision applications, the calibration of camera parameters is a crucial link, especially in vision measurement applications, where the calibration accuracy directly affects the accuracy of the entire measurement system. Camera calibration requires a calibration plate with a special structure to extract precise point-line features. At present, there are mainly two types of calibration boards in the prior art: checkerboard calibration boards and dot-shaped calibration boards. Among them, the checkerboard calibration board obtains point features by locating the corner points of the checkerboard. In order to ensure the extraction accuracy of the corner points, higher imaging quality is usually required. The dot-type calibration plate obtains point features by locating the ce...

AI Technical Summary

Problems solved by technology

The disadvantage is that the positioning reference is on the frame, and the calibration board needs to be completely within the field of view; and the corresponding algorithm requires that the marker points need to be detected exactly, which cannot adapt to the situation of shortcomings or noise points, and the robustness is not good

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