A low refresh-rate video sequences compression technique using quadtrees and adaptive spatial sampling

In this paper, a compression chain for digital images is described that achieves high compression ratios and stable quality over long periods without the need for frequent generation of reference frames. The compression algorithm described thus proposes an innovative solution for the transmission of the refresh information which is the usual cause of bit rate peaks and/or decoding delays if smoothing is applied to these peaks. Experimental results show that for at least 100 frames, the quality is constant enough not to request any generation of intra-coded frames. The technique is quite general as it doesn't make any assumption about the image type. The best results are obtained for sequences with medium-to-low motion such as those encountered in video phone and video conference applications or remote surveillance systems.