Abstract
Communicating color gamut is very important in color research and application. The problem of calculating image gamut, however, has no definitive solution yet. We propose a new method for calculating the gamut volume by rearranging the color values. The entire color space is firstly divided by hue angle ΔHab and secondly by lightness ΔL where the steps (ΔHab, ΔL) are decided in non-uniform to include the constant color samples in each segmented sectors. And the most out-side points from the center are extracted. In previous paper, the entire gamut volume was calculated by summing up the individual volume of tetrahedral with selected color values, but this volume was calculated bigger than theoretical values. In this paper, ΔL division is changed by lightness angle ΔLangle, and triangle surfaces constructed by each ordered points are decided an outer or inner side. A tetrahedron constructed by inner side surface is assigned a minus volume. As a result, the corresponding color gamuts are exactly calculated and analyzed. This method is available to describe the surface of image color gamut.
