Title :
Minimax multiresolution scalar quantization
Author :
Sarshar, Nima ; Wu, Xiaolin
Author_Institution :
McMaster Univ., Hamilton, Ont., Canada
Abstract :
We consider the problem of design and analysis of optimal L∞ (minmax) multiresolution scalar quantizers (MRSQ). The overall multiresolution L∞ distortion of an MRSQ is denned to be a weighted sum of L∞ distortions over all refinement levels of the MRSQ. The weight for a refinement level usually denotes the probability that the MRSQ will operate at that level (rate). An interesting relation of the problem to the design of optimal binary prefix codes under a code cell contiguity constraint is established: Lower bounds for the overall multiresolution L∞ distortion are derived based on this relation. Provably optimal as well as fast, near optimal algorithms are also developed for practically interesting scenarios. Furthermore, the performance penalty incurred by making a scalable quantizer embedded (progressively refinable) is analyzed. It is shown that constraining the quantizers to be embedded would on average increase the L∞ quantization error by at least 44%.
Keywords :
binary codes; distortion; error analysis; image coding; image representation; image resolution; optimisation; quantisation (signal); source coding; code cell contiguity constraint; minimax multiresolution scalar quantization; multiresolution distortion; multiresolution signal representation; optimal binary prefix code; optimisation; probability; progressive code; quantization error analysis; quantizer embedding; weighted sum distortion; Additives; Distortion measurement; Force measurement; Image coding; Minimax techniques; Multiresolution analysis; Performance analysis; Quantization; Random variables; Signal resolution;
Conference_Titel :
Data Compression Conference, 2004. Proceedings. DCC 2004
Print_ISBN :
0-7695-2082-0
DOI :
10.1109/DCC.2004.1281450