An unequal error protection method for progressively compressed 3-D meshes

In this paper, we present a packet-loss resilient 3-D graphics transmission system that is scalable with respect to both channel bandwidth and channel error characteristics. The algorithm trades off source coding efficiency for increased bit-stream error resilience to optimize the decoded mesh quality on the client side. It uses the Compressed Progressive Mesh (CPM) algorithm to generate a hierarchical bit-stream representing different levels of details (LODs). We assign optimal forward error correction (FEC) code rates to protect different parts of the bit-stream differently. These optimal FEC code rates are determined theoretically via a distortion function that accounts for: the channel packet loss rate, the nature of the encoded 3-D mesh and the error protection bit-budget. We present experimental results, which show that with our unequal error protection (UEP) optimal approach, the decoded mesh quality degrades more gracefully (compared to either no error protection (NEP) or equal error protection (EEP) methods) as the packet loss rate increases.