A Calibration Corner Detection Method Based on 180° Rotation Operator

Abstract

The invention discloses a calibration angle point detection method based on a 180-degree rotating operator. The method comprises the steps of (1) acquiring a calibration image I to be treated; (2) determining gray level variation value I; (2) determining gray level variation degree Z1; (3) determining 180-degree rotating overlap ratio Z2; (4) extracting angle points of the image. According to the method, a die plate based on the 180-degree rotating operator is designed according to the rotating symmetry of patterns surrounding checkerboard angle points on three surfaces of a calibration block, so as to achieve the efficient detection for the angle points of the calibrating block; the experiment data and result analysis show that the method is high in accuracy and stability in angle point detection, applicable to the general calibration image and multi-surface calibration image, and has the same effect on the calibration image with a certain of inclination degree and deformation.

Description

technical field [0001] The invention relates to the field of image processing in surface mounting equipment, in particular to a method for quickly and accurately detecting corner points in camera calibration based on a 180° rotation operator. Background technique [0002] Camera calibration is an important part of machine vision and image processing, and its accuracy determines the performance of the entire 3D measurement system in many cases. In the series of equipment for precision electronics manufacturing, surface mount equipment is used to mount components on PCBs. Therefore, the importance of equipment system accuracy is self-evident. In general, the checkerboard image is used as the calibration image, and the corner points are the points where the brightness change of the image is very different from that of adjacent points. Corner detection is an important part of camera calibration. By extracting the corner position information on the image, the relationship betw...

AI Technical Summary

Problems solved by technology

Manually obtain the position information of the corner points, the existing problems are: first, manual intervention is required

It affects the speed of the camera calibration image processing process, and there is no way to achieve dynamic calibration; secondly, the detection accuracy of corner points is unstable, which will also be related to the operator's experience to a certain extent, etc.

In the automatic detection method, although Harris operator, Susan operator, etc. can be used to realize the automatic calibration process, but the accuracy is unstable, false corners, etc., especially in the tilted checkerboard image, which affects the entire Camera Calibration Accuracy

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