Target correction method and system

Abstract

The invention is applicable to the field of machine visual and three-dimensional measurement and provides a target correction method and system. The embodiment of the invention provides the target correction method, comprising the following steps of: photographing a target from different angles to obtain a plurality of images; respectively extracting the center of a marking point in each image as a characteristic point and establishing a corresponding relation of the marking points with the same name between the images; combining a close-range photogrammetry technology to calculate a three-dimensional coordinate of the characteristic point, wherein the three-dimensional coordinate is restrained by a scale factor; finally obtaining the scale factor and zooming the three-dimensional coordinate of each characteristic point to an actual size. The target manufactured and corrected by the method has the advantages of higher precision, easiness for operation and low cost. Meanwhile, the scale factor is obtained by adopting a fringe projection measurement system and a standard ball, the correction precision is higher and the relative precision (absolute precision / target size) can reach 1:1000. Therefore, the method and the system provided by the invention can be widely applied to the vision measurement and the system calibration.

Description

technical field [0001] The invention belongs to the field of machine vision technology and three-dimensional measurement, and in particular relates to the production and correction of a target for camera calibration. Background technique [0002] Camera calibration is a key technology in the field of computer vision and three-dimensional measurement, and camera calibration requires a high-precision target, and the accuracy of the target determines the accuracy of camera calibration and measurement. Usually a high-precision target is complicated to manufacture and process, and the cost is high; at present, there are usually two ways to obtain a two-dimensional planar target with an accuracy of micron level: the first one requires high-precision processing equipment, In order to ensure that the distance accuracy of the marking points on the target reaches the micron level; the second is to use a two-dimensional imager with micron level precision to measure the distance or coor...

AI Technical Summary

Problems solved by technology

For general planar targets, taking circular markers as an example, the shape (roundness and edge) of the markers can meet the accuracy requirements, but the coordinate accuracy of the center of the circle is difficult to guarantee

If other means (such as a two-dimensional image measuring instrument) are used to measure the exact position of the marker points one by one, it is often time-consuming and laborious

Images