Novel codebook generation algorithms for vector quantization image compression

Novel algorithms for vector quantization codebook design are presented. Two basic techniques are proposed. The first technique takes into consideration specific characteristics of the blocks of the training sequence during the generation of the initial codebook. In this way a representative initial codebook is generated. Starting from a high quality initial codebook the iterative optimization procedure converges fast to representative final codebook which in turn leads to a high output image quality. The second proposed technique extends small codebooks computationally. The main idea is the application of simple transformations on the codewords. This technique reduces the memory requirements of the traditional vector quantization making it useful for applications requiring low-power consumption