Scan-based compression of 3D mesh sequences with geometry compensation

We introduce in this paper a new compression process to encode the geometry of 3D mesh sequences (with a fixed connectivity). The proposed method uses a scan-based wavelet transform with an original approach which consists to compensate the geometry displacements of the mesh sequence. The proposed coder is based on temporal lifting scheme and bit allocation using statistical models for the probability densities of the temporal wavelet coefficients. Then, scalar quantization and entropy coding are used to encode the quantized subbands and the geometry displacement vectors. The resulting compression scheme shows that good coding performances are obtained when the compensation of the geometry is done on the whole sequence, which requires large memory. Furthermore, we showed that when low memory scan-based compression is done, the performances of the encoder approach the ones obtained when the whole sequence is known. Also, simulation results show that the proposed algorithm provides better compression performances than some state of the art coders.