ADAPTIVE JPEG LOSSY COMPRESSION OF COLOR IMAGES
Nikolay N. Ponomarenko, Владимир Васильевич Лукин, Karen Egiazarian, Leena Lepistö · Telecommunications and Radio Engineering · 2011
JPEG based compression of color digital images in visually lossless manner with adaptation to image/distortion characteristics and providing appropriately large compression ratio is considered. Adaptation is performed for raw images with taking into account further nonlinear transformations carried out in imaging devices as digital cameras before compression. Blur and noise parameters are estimated and/or predicted and they serve for setting a proper quantization table for JPEG compression. The proposed approach is tested for a large number of real life color photos. It is demonstrated that compression ratio can be on the average increased by about two times compared to super-high quality (SHQ) mode used in modern digital cameras. No visible differences are observed between images compressed by adaptive JPEG and in SHQ mode.