Color three-dimensional imaging system based on three cameras and calibration method thereof

Abstract

The invention provides a color three-dimensional imaging system based on three cameras and a calibration method thereof, and the method comprises the steps: respectively collecting a first image, a second image and a third image containing a target through a left camera, a right camera and a color camera, and obtaining pixel coordinates of a mark point in the first image, the second image and thethird image; calibrating a binocular system consisting of the left camera and the right camera by utilizing a backward projection principle of the left camera and the right camera according to pixel coordinates of the mark point in the first image and the second image to obtain a first calibration parameter; and calibrating the color camera by utilizing a forward projection principle of the colorcamera according to the external parameter matrix of the left camera and the pixel coordinates of the mark points in the third image to obtain a second calibration parameter. An imaging model is reconstructed for the left camera and the right camera through backward projection, and binocular system calibration is completed. Forward projection is utilized to complete color camera calibration on thecolor camera reconstruction imaging model, so that the calibration optimization objective function is consistent with the color three-dimensional reconstruction process, and the calibration precisionis improved.

Description

[0001] 【Technical field】 [0002] The invention belongs to the technical field of three-dimensional measurement, and in particular relates to a color three-dimensional imaging system based on three cameras and a calibration method thereof. [0003] 【Background technique】 [0004] Camera calibration is an essential step in image measurement or machine vision applications. The accuracy of the calibration results and the stability of the algorithm directly affect the accuracy of the camera work results. Usually, the calibration method of a color 3D imaging system based on three cameras is realized based on two grayscale cameras and one color camera: a binocular stereoscopic imaging system is formed by forming a certain angle between two grayscale cameras on the left and right. The structural parameters of the binocular stereo imaging complete the 3D reconstruction of the binocular stereo imaging system; then according to the coordinate transformation relationship between the color...

AI Technical Summary

Problems solved by technology

[0005] However, in the calibration process of the color 3D imaging system based on three cameras in the prior art, the error between the actual value and the theoretical value of the image coordinates of the three cameras is mostly used as the optimization objective function

This calibration method does not take into account the projection error of the reconstructed 3D model in the color camera, that is, the distance between the projection position of the reconstructed 3D model obtained through the imaging of the color camera and the real imaging image position, resulting in a relatively large error in the final calibration result. Large, low precision

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