Stereoscopic scenes of the mankind is naturally caused by synthesizing two images produced by the parallax of the two eyes of human. Such being the case, mankind can distinguish the relative position of the objects. In the study of related stereovision, some persons aim at the framework of taking simulated images with two eyes using one or two cameras from front and back or simultaneously at the same time to obtain a pair of parallax mages; someone pay more attention to the theoretical analysis of the relative positions of the parallax images, and some others do the work of using parallax images as material to carry out the job of image classification, comparison and analysis. The purpose of this paper is to estimate the distance between the objects and the camera in an outdoor environment using commercial digital camera. Key words: computer vision, machine vision, stereoscopic, object depth, binocular disparity, depth perception.