A Virtual Color Space Based on Physical Model
基于物理模型的虚拟颜色空间

The measurement of color difference in machine vision is the basement of image segmentation based on the color features, but there is no colorimetrical system for machine vision. Traditional colorimetry has two major systems: (1) to build a color specification system experimentally and to use it as a reference (for example, the Munsell Book of Color). (2) to develop an analytical formulation based on discrimination experiments (such as, CIELAB, CIELUV). The color space based on the psychophysical experiments of human visual system is non-flat. That means the perceptual difference of colors can not be described by the Euclidian distances between the related two points in the color space and the map from perceptual difference to the Euclidian distances is not linear. In this paper, we built a virtual color space based on the physical models of light, reflectance of surfaces and the sampling function of visual system. In this virtual color space the chromatism of machine vision can be calculated linearly. We also suggest that the chromatism measurement of machine vision is different from the spectral reflectance of physical surfaces used in present computer models of color vision.