Image Coding By Vector Quantization In A Transformed Domain
Claude Labit, Jean-Pierre Marescq · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1986
Using vector quantization in a transformed domain, TV images are coded. The method exploit spatial redundancies of small 4x4 blocks of pixel : first, a DCT (or Hadamard) trans-form is performed on these blocks. A classification algorithm ranks them into visual and transform properties-based classes. For each class, high energy carrying coefficients are retained and using vector quantization, a codebook is built for the AC remaining part of the transformed blocks. The whole of the codeworks are referenced by an index. Each block is then coded by specifying its DC coefficient and associated index.