Fast search algorithm for vector quantisation without extra look-up table using declustered subcodebooks

A fast search routine is presented to be used in the encoding phase of vector quantisation (VQ). The routine applies the technique of declustering to split a codebook into several subcodebooks. Then, the appropriate codeword can be found by using the constructed subcodebooks. According to the experimental results, the method can indeed provide good image quality and an efficient coding process. Furthermore, the extra memory space used in the search routine is not needed in the method. Thus, this method provides a practical solution for implementing the search routine in VQ.