VS + OpenCV based binocular vision for A4 paper length measurement

Binocular vision ranging is becoming more and more widely used. In this paper, based on the principle of binocular camera ranging, a binocular ranging system is built with the help of Win10+VS2017+0penCV3.4.6. The calibration of the binocular camera is completed using the Zhang Zhengyou chessboard calibration method and Matlab2017b calibration toolbox. On the basis of BM matched ranging, the method of Canny edge detection, Sobel edge detection and Scharr filter edge detection edge detection followed by BM matched ranging was proposed to obtain the 3D information of the target point on the parallax map, and the difference of the effective target point to the x coordinate was the length of the measured paper. The experimental results demonstrate that the canny edge detection followed by BM matching distance measurement method yields more accurate results with a smaller error of 1.6% or less.