3D profile measurement by color pattern projection and system calibration

In this paper, we present a new color structured lighting for 3D profile measurement by projecting a pattern of color stripes. The advantage of using color pattern is that it simplifies the difficult matching problem of using a multiple-line stripe pattern. The problem of finding the correct color stripe correspondence between a light source and images is solved by accurately calibrating the system parameters. A technique for camera-projector calibration using the calibration points that projected from a projector is presented. The mean error of this calibration method is about 0.2 mm. A pattern of color stripes is projected onto the objects when taking images with cameras from various viewpoints, and the stripe pattern information are extracted from the acquired images and then used for finding the correct projected-observed stripe match. After the matched stripes information was obtained, a 3D profile is then reconstructed by means of triangulation. The selection of color used to generate the color-stripe pattern is presented. An experiment using human hand as a model is also demonstrated.