Vector representation of chrominance for very low bit rate coding of video

A chrominance vector quantization technique is proposed as a preprocessing step prior to any kind (e.g. DCT-based or OBASC) of video coding. The operation converts the stream of two-component vectors into a scalar stream of chrominance labels. Therefore the coder processes two channels only: one luminance and one chrominance. After decoding the two chrominance channels are reconstructed from the stream of labels of chrominance codebook entries. Experimental results with still images show recognizable improvement of the subjective quality by a constant compression ratio.