Entropy-constrained geometric vector quantization for transform image coding

A noiseless code is combined with a lattice-based vector quantizer (VQ). For small distortion encoding of Laplacian data, the noiseless code has redundancy of at most 2/L, where L is the vector dimension. The VQ and noiseless code are used in discrete cosine transform image coding. An image coder using a single VQ/noiseless code yields performance roughly equivalent to a benchmark coder using entropy-constrained scalar quantization with entropy codes designed for each transform coefficient. The use of several VQ/noiseless codes can further reduce the encoding rate