Method and system for correcting circle center deviation of round mark points during camera projection transformation

Abstract

The invention discloses a method and a system for correcting the circle center deviation of round mark points during camera projection transformation. The method for correcting comprises the following steps of: step A, arranging the round mark points which have colors different with a background and have concentric ring shapes; step B, shooting the round mark points by utilizing a camera, carrying out sub-pixel positioning on the edges of the shot image of the round mark points, and fitting a large ellipse and a small ellipse according to the positioned sub-pixel edges; and step C, according to the radiuses r1 and r2 of a large circle and a small circle which are concentric and are obtained in the step A and the center coordinates C1 (muB1, vB1) and C2 (muB2, vB2) of the large ellipse and the small ellipse which are obtained in the step B, correcting the image coordinates of the practical projective points of the circle centers of the round mark points on an image plane after the camera projection transformation. A concentric ring method is adopted, and the linear combination of the large ellipse and the small ellipse is ingeniously utilized to correct the real positions of the circle centers of the manual round mark points on the image plane.

Description

technical field [0001] The invention belongs to the field of computer image processing, and in particular relates to a method and system for correcting circle center deviation of circular marker points in camera projection transformation. Background technique [0002] In computer vision and 3D detection, circular landmarks are widely used for calibration of system parameters and global matching of depth data. In practice, it is necessary to determine the image coordinates of the center of the circle marker point with high precision in the digital image formed by the camera. Generally, the projection of the circle center of the marker point is directly determined by fitting the center of the ellipse formed by the circle marker in the image. point. But when the imaging plane of the camera is not parallel to the object plane where the marker point is located, the center of the ellipse in the image is not the projection point of the circular marker point on the image plane afte...

AI Technical Summary

Problems solved by technology

This method needs to use the centers of two ellipses, large and small, to fit the equation of a straight line passing through these two centers, and then find the intersection of the line and the two ellipses, in practice, the distance between the centers of two ellipses is usually very small, and the distance between the two ellipses is very small. The nearest point is used to fit the straight line, which requires high precision for the center of the two ellipses, and the robustness is not very good

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