2 – COLOR SPACES

Publisher Summary This chapter discusses color spaces. The XYZ color space is not an intuitive space. It is difficult to interpret the meanings of the values for X and Z, though Y was designed to represent the brightness of a color. In addition to an intuitive interpretation of the axes, an ideal color space would be perceptually linear. Thus, a particular magnitude of shift in color space at one point may be undetectable, but the same shift applied to a different color would be quite visible. One particularly important feature of these spaces is that two pairs of colors with the same distance metric are almost perceptually equally similar or different. Much of the color computation in computer graphics has historically been done in RGB space. Many applications of computer graphics require the use of accurate color representations of natural objects. A blade of grass, a piece of obsidian, and a tin can all have specific reflectivities that may be carefully measured. The best way to describe these colors is probably with some form of spectral radiant power distribution.