Multiple-description geometry compression for networked interactive 3D graphics
An existing technique for robust streaming of 3D graphics contents over lossy networks is multi-resolution coding of 3D geometry. An advantage of this approach is that it uses refinement layers and therefore multiple clients with different bandwidths can be served by a single unified code stream. However, there is a dependency between refinement layers, called prefix condition. Decoding of a given layer requires the knowledge of all the previous layers. A problem in the base layer reception interrupts the streaming all together and voids the remaining layers even though they are received perfectly. To overcome this drawback, this paper proposes an alternative approach to multi-resolution geometry coding, called multiple-description coding of 3D geometry. Instead of organizing code stream into embedded layers, MDC generates several separate descriptions of a geometric object, called co-descriptions. Each co-description of MDC can be independently decoded without any knowledge of other co-descriptions. Each extra successfully received co-description improves the fidelity of reconstructed geometry regardless of what has been received so far or in what order.