Development of XYZ/sRGB-SCID and Color Gamut Mapping

The new work items for ISO/TC130/WG2 include preparation of new standard images to cope with the future multi-media prevalence. The new standard images consist of an Lab-SCID set prepared by the Switzerland team and an XYZ/sRGB-SCID by the Japanese team. The paper describes the definition of XYZ/sRGB-SCID color space and the preparation of standard images. XYZ/sRGB-SCID has been developed particularly for the monitor d splay of natural and synthetic images. The color space defined by XYZ/sRGB-SCID has a high degree of consistency from image input to monitor output: such a desirable feature has been achieved by adopting the ITU-R BT.709-3 standard as the image capturing norm and sRGB as the monitor display norm. As the two standards arc both based on D65 light source, the present standard pictures imply those in a D65 color space. The image data for a natural picture have been prepared by first shooting an original scene with a color reversal film, converting the recorded XYZ color coordinates back to those of the original scene, then applying mace processings such as one making the image displayed on an sRGB monitor subjectively favorable, color gamut compression taking into account the sRGB monitor gamut for reproducible colors, etc. XYZ/sRGB-SCID is described in terms of 16 bit XYZ and 8 bit RGB color data with a resolution of 4k × 3k. The present standard images, comprising stable and reliable high quality image data, are extensively useful for the evaluation of the color reproducing capability of imaging systems, the evaluation of color image output devices. coding techniques associated with the storage and transmission of high resolution image data, etc.