A NOVEL ALGORITHM FOR LOW-POWER IMAGE AND VIDEO CODING

A novel scheme for low-power image and video coding and decoding is pr esented. It is based on vector quantization, and reduces its memory re quirements, which form a major disadvantage in terms of power consumpt ion. The main innovation is the use of small codebooks, and the applic ation of simple but efficient transformations to the codewords during coding to compensate for the quality degradation introduced by the sma ll codebook size. In this way, the small codebooks are computationally extended, and the coding task becomes computation based rather than m emory based, leading to significant power consumption reduction. The p arameters of the transformations depend on the image block under codin g, and thus the small codebooks are dynamically adapted each time to t his specific image block, leading to image qualities comparable to or better than those corresponding to classical vector quantization. The algorithm leads to power savings of a factor of 10 in coding and of a factor of 3 in decoding at least, in comparison to classical full-sear ch vector quantization. Both image quality and power consumption highl y depend on the size of the codebook that is used.