Abstract: Aiming at the problem that the similarity measures in the overwhelming majority of stereo matching approaches rely heavily on the statistical characteristics of image gray values,a stereo matching algorithm insensitive to differentiations in illumination is proposed.Firstly,the Census non-parametric transform is investigated and its limitations are analyzed. Secondly,in order to take the pixels' spatial location information into consideration when searching stereo correspondences, gray values of the neighborhood pixels,whose relative positions are one unit greater than the center pixel in the transformation window,are replaced by gray values' interpolation with the four pixels adjacent to them.Finally,the Census non-parametric transform of images and stereo matching are implemented,and then,dense disparity map is obtained.The experiment results show that the proposed method has simple mechanism,high computational efficiency and strong robustness;satisfactory stereo matching results also can be obtained even under non-ideal illumination conditions.