Efficient search algorithm for fast encoding of images using vector quantisation

A fast algorithm for image coding using vector quantisation which exploits the spatial redundancies in the image is proposed. The algorithm speeds up the codeword search phase required for nearest neighbour encoding, by utilising the high amount of intravector and intervector correlations. A novel prediction mechanism is used to exploit the intervector correlations and a mean pyramid representation is used for exploiting the intravector correlations. The prediction mechanism also enables a further reduction in bit rate compared to ordinary vector quantisation. Simulation results show the effectiveness of the proposed method