3D head model generation using full-face head shape measurement system

Recently, the application of human facial shapes has been attracting interest in such fields as authentication, amusement, and medical care. However, the systems now used in practice heavily burden the person undergoing measurement, because a long time is required for measurement and the user must maintain his or her facial expression. The paper considers the measurement of the human face and proposes a fast method for head shape measurement in which the number of projected patterns is decreased by utilizing the continuity of the facial shape and the uniformity of its reflectivity. Specifically, based on the assumption of continuity of the facial shape, the pattern projection of the upper bits is omitted in the spatial coding, and the spatial code is restored by utilizing the continuity of the facial shape. By applying this method, shape measurement with 8-bit spatial resolution in the depth direction is achieved by five pattern light projection operations. Based on the fact that the reflectivity of the face is almost uniform, binarization is performed without complementary pattern projection, by using average image comparison and local threshold setting. With these measures, the head model can be acquired by the proposed method in 14 pattern imaging operations, compared with 36 pattern imaging operations required in the conventional measurement system based on spatial coding using complementary pattern light projection. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(13): 82–91, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ scj.20377