Secondary codebook storage quantisation

Efficient reduction of storage and complexity demands in VQ and MQ systems is a key issue when developing new, more powerful compression algorithms. Secondary Storage Quantisation (SSQ) is capable of drastically reducing VQ storage through an efficient representation of codebook elements. Rather than the conventional fixed or floating point representation, codebook elements are quantised using a set of “secondary codebooks” and represented as a set of quantisation indices. The number of bits required for these indices is relatively small and hence the amount of storage required for codebook representation is reduced. The potential of SSQ for codebook compression is demonstrated in a Split Matrix Quantisation (SMQ) application. A reduction of 65 75 % in the amount of memory required for SMQ codebooks is achieved.