A runlength coded ldpc scheme for insertion/deletion correction in multimedia watermarking

We describe a simple and effective coding scheme for insertion/deletion channels. It is based on runlength coding which converts a class of insertion/deletion channels that have infinite memory into memoryless channels, which are much easier to handle. Runlengthcoding is then combined with powerful error correction low-density parity-check (LDPC) codes designed for memoryless channels. We consider a novel applications of this technique in multimedia watermarking using quantization index modulation operating on the three dimensional mesh vertices. The runlength LDPC coding recovers the data hidden in the vertices removed by the process of mesh simplification.