Noiseless coding of VQ index using index grouping algorithm

In a memoryless vector quantization (VQ) of images, each image block is quantized independently, while its corresponding index is sent to the decoder. Since the image blocks are highly correlated, many blocks may correspond to the same index. This paper presents a noiseless coding algorithm which groups up the blocks with the same index and then encodes the group path efficiently. Simulation results indicate that the new algorithm improves coding efficiency without introducing any extra loss of information.