Image-dependent Gamut Compression and Extension

摘要

Gamut mapping from displayed image onto print is a current topic in cross-media color reproduction Current gamut mapping algorithm (GMA) is mostly addressed to compress the out-of-gamut colors into the inside of printer gamut. Indeed, the highly saturated CG images or electronic paintings on monitor should be compressed to make the appearance matching to print. However, the printer gamut has been much expanded with the improvements in printing media. Hence, source image doesn't always fulfill the entire device gamut, and sometimes its gamut had better to be extended for the better color renditions. Current GMAs are designed to work in 2-D lightness-chroma planes based on device-to-device (D-D) gamut relations not on image-to-device (I-D). Of course, I-D GMA is preferable than D-D and is desirable to map the colors directly and seamlessly in 3-D color space. Our approach is based on I-D and directed toward seamless real 3-D mapping. This paper proposes an advanced GMA coupling the two types of mappings, one for compression and the other for extension. The mapping results narrow from/to wide gamut are reported.