Virtual structured-light coding for three-dimensional shape data compression

In order to reduce the file size of three-dimensional (3D) shape data, we propose two compression algorithms: two-channel phase coding algorithm and three-channel phase coding algorithm. In these two algorithms, 3D shape information is encoded into the color channels of a single 24-bit color image based on virtual structured-light projection system. Tested with a hemisphere of 1 mm diameter used in another virtual structured-light coding algorithm, which was proposed by Nikolaus Karpinsky and Song Zhang in 'composite phase-shifting algorithm for three-dimensional shape compression' in 2010, the two-channel phase coding algorithm achieves compression ratio 1:56.6 with reconstruction error of +/- 4.91 x 10(-4) mm, and the three-channel algorithm gains compression ratio 1:33.8 with reconstruction error of +/- 0.36 x 10(-4) mm. The theoretical analyses demonstrate that the relative reconstruction errors of our coding algorithms can be reduced to 7.66 x 10(-6) and 2.99 x 10(-8) of the height of the 3D object, respectively. With these theoretical analyses, the virtual structured-light coding algorithms can be used to achieve desired reconstruction qualities with high compression ratios in storing, transmitting, encrypting 3D shapes and constructing 3D face databases. (C) 2012 Elsevier Ltd. All rights reserved.