High-quality still color image compression
Frédéric Truchetet · Optical Engineering · 2000
A wavelet packet transform algorithm for color still images is presented and we show how and with what performances the trans- formed image tree can be pruned and the imagets altered to obtain a compression/decompression algorithm respectful of human psychovi- sual image perception. The basic assumptions for human vision on which the algorithm has been constructed are presented; and we deal with the color transformation used before applying wavelet packet trans- form. We also point out that a quasi-lossless compression/ decompression scheme can be easily obtained with a compression ratio up to 1:10 (quantization step was not considered here). Finally, a new quality criterion based on the results of tests on human sensitivity to various scale and color image details is proposed. This figure of merit can be considered a multiresolution release of the most commonly used peak SNR (PSNR) criterion. © 2000 Society of Photo-Optical Instrumentation En- gineers. (S0091-3286(00)01102-8)