Secondly，the stereo matching way based on feature has been studied，takes the

preprocess method fit for the task．In image segmentation，this paper proposes serfadaptive

threshold method which has been changed a bit to make it more suitable for the

task．In feature extracting，because of affect of shadow，and object has circle’S

character，therefore Hough transformation is applied to accurately extract object’S

centre of the circle．Then feature matching of left image’S object and fight image’object

under the constraint of epipolar line．