Patent ID: 7471809

Claim:
A method for processing a stereo image, for measuring parallax by making a stereo-correspondence search between a base image taken with a first imaging device and a reference image taken with a second imaging device, comprising the steps of: setting a specified area of a base window with reference to an object point for obtaining a corresponding point in the base image; setting a reference window having a same size as that of the base window in the reference image; evaluating a difference between patterns of the base window and the reference window while scanning the reference window along an epipolar line in the reference image which corresponds to the object point; determining a position of the reference window having a minimum difference as a stereo corresponding point; measuring the parallax by a difference between a position of the base window and a position of the reference window when the stereo-corresponding point is determined; calculating a reliability of the parallax by first reliability based on a sharpness of a peak of an evaluation-value distribution of the difference of patterns between the base window and the reference window obtained by scanning the reference window and second reliability based on a shape of the peaks; and outputting a value of the reliability of the parallax together with a value of the parallax.