In the last several years, tremendous progress has been made toward the development of international standards for Color Facsimile within the International Telecommunication Union—Telecommunication Standard Sector, ITU-T (formerly called the CCITT). The first goal of these efforts is to encode and communicate full-color continuous-tone images using the JPEG image compression standard and the CIELAB color space as the color interchange space. For this goal, ITU-T Recommendation T.42 “Continuous-tone colour representation method for facsimile” and new annexes and revised recommendations for Group 3 and Group 4 facsimiles were developed and approved by ITU-T in 1994. The next goals of these efforts are soft-copy and palletized color image extensions for color facsimile. For soft-copy facsimile, color interchange space and optional color reproduction information are being proposed at ITU-T. For encoding palletized color images and lossless continuous-tone images, the JBIG image compression method is being considered by ITU-T. The recent progress in the above proposals are reported in this paper.
Makoto Matsuki, Daniel T. Lee, Andrew H. Mutz, Hiroaki Ikegami, "Soft-Copy and Palette-Color Extension for Color Facsimile Standards" in Proc. IS&T 3rd Color and Imaging Conf., 1995, pp 174 - 177, https://doi.org/10.2352/CIC.1995.3.1.art00046