An application of fixed-rate scalar-vector quantization in image coding

Considers an application of a structured, fixed-length vector quantizer, called the scalar-vector quantizer, to image coding. The scalar-vector quantizer, while using fixed-length codewords, achieves a rate-distortion performance close to that of the optimum variable-length encoded scalar quantizer. In the paper, an adaptive 2D DCT coding system is developed in which the DCT coefficients are quantized by scalar-vector quantizers. It is shown that performance comparable to variable-length coding systems can be achieved while maintaining a fixed encoding rate. Preliminary results on the performance of the proposed system when employed over a noisy channel, along with a simple error mitigation mechanism are also provided.