Patent ID: 6697434
Filing Date: 2004-02-24
Classification: H04N

Abstract:
In a Trellis-based adaptive quantizer codes coefficient to which image blocks are transformed by transformation methods in a Trellis structure into a run-length code and entropy constrained code, a method for tracing an optimal path using the Trellis-based adaptive quantizer, comprising the steps of:preventing quantization path tracing of branches after a turning point of distortion, on the basis of arrangement of a quantization interval and monotonic increasing characteristics of a code word length, in a Trellis structure that forms stages corresponding to quantized coefficients whenever the coefficients are quantized one by one from a node; and preventing path tracing after an optimal coding level to non-zero at the branches positioned from zero node to non-zero node, based on independence of the formed stages, when quantizing coefficients to non-zero node from the node.