Simultaneous perimeter measurement for 3D object with a binocular stereo vision measurement system

A simultaneous measurement scheme for multiple three-dimensional (3D) objects’ surface boundary perimeters is proposed. This scheme consists of three steps. First, a binocular stereo vision measurement system with two CCD cameras is devised to obtain the two images of the detected objects’ 3D surface boundaries. Second, two geodesic active contours are applied to converge to the objects’ contour edges simultaneously in the two CCD images to perform the stereo matching. Finally, the multiple spatial contours are reconstructed using the cubic B-spline curve interpolation. The true contour length of every spatial contour is computed as the true boundary perimeter of every 3D object. An experiment on the bent surface's perimeter measurement for the four 3D objects indicates that this scheme's measurement repetition error decreases to 0.7 mm.