Rate-distortion optimized compression and view-dependent transmission of 3-D normal meshes

A unified approach to rate-distortion (R-D) optimized compression and view-dependent transmission of three-dimensional (3-D) normal meshes is investigated in this work. A normal mesh is partitioned into several segments, which are then encoded independently. The bitstream of each segment is truncated optimally using a geometry distortion model based on the subdivision hierarchy. It is shown that the proposed compression algorithm yields a higher coding gain than the conventional algorithm. Moreover, to facilitate interactive transmission of 3-D data according to a client´s viewing position, the server can allocate an adaptive bitrate to each segment based on its visibility priority. Simulation results demonstrate that the view-dependent transmission technique can reduce the bandwidth requirement considerably, while maintaining a good visual quality.