Error resilient hybrid variable length codec with tough error synchronization for wireless image transmission

Variable-length codes, also called Huffman code, is the most popular data compression technique used for solving channel bandwidth bottleneck in many image compression standards such as JPEG, MPEG-2, and H263. But, it is vulnerable to loss of synchronization if they are transmitted consecutively through a noisy channel. It will result in large drops in image quality. Previously, we have proposed a novel HVLC coding scheme, which exhibits high synchronization, error correction capability and low redundancy. Simulation results show that it can achieve high signal-to-noise ratio (PSNR=28 dB) compared to existed VLC schemes at bit error rate (BER) of 10^-3 environment. Here, we present HVLC codec system. It can support up to 256-entry 12-bit symbol table. The codec system provides advanced options and fully programmable for pixel-based and DCT-based image coding algorithm. Based on 0.35 um CMOS SPQM technology, the codec system occupies a silicon area of 3400 um×3400 um and consists of 88,000 gate count. It can operate at 3 V power supply and yields high encoding/decoding rate of 133 M-Symbol/sec for real time application requirement