Usually, the stereo correspondence for a feature point in the first image is obtained by searching in a predefined region of the second image, based on the epipolar line and the maximum disparity. The reduction of the search space can increase the performance of the matching process, in the con-text of the execution time and the accuracy. For the edge-based stereo correspondence, we obtain the noticeable reduction in the search space. Con-sidering the maximum of the disparity gradient in the real scene, we formulated the relation between the maximum search space in the second images with respect to the relative displacement of the continuous edges (as the feature points) in the successive scan lines of the first images. Then we developed some very fast stereo matching algo-rithms, based on the normalized cross correlation criteria (NCC) for different sizes of the matching block.
