Perceptual preprocessing techniques applied to video compression: some result elements and analysis

Summary form only given. The developments in video coding research deal with solutions to improve the picture quality while decreasing the bit rates. However, no major breakthrough in compression emerged and low bit rate high quality video compression is still an open issue. The compression scheme is generally decomposed into two stages: coding and decoding. In order to improve the compression efficiency, a complementary solution may consist in introducing a preprocessing stage before the encoding process or/and a post-processing step after decoding. For this purpose, instead of using the usual (Y, U, V) representation space to compress the video signal, where the video is encoded along different separate channels (luminance Y, chrominance U, chrominance V), we propose to choose other channels by means of a color preprocessing based upon perceptual and physics-based approaches. We compare an original H.26L encoder (ITU standard for video coding), i.e. without preprocessing, and the same H.26L encoder with a preprocessing stage to evaluate the extent to which the preprocessing stage increases the compression efficiency, in particular with perceptual solutions.