Color image segmentation with detection of highlights and local illumination induced by inter-reflections

A computational model for color image segmentation is proposed based on the physical properties of sensors, illumination lights, and surface reflectances. For image segmentation to depend only on the change of material surface, variations of surface reflection due to illumination, shading, shadows, and highlights should be discounted from a measured image. The authors use the dichromatic model for dielectric materials and develop a metric space of intensity, hue, and saturation in order to interpret various light-surface interactions better. Using the established model for surface reflection, the authors perform color image segmentation based on the material change with detection of highlights and small interreflections between adjacent objects. A reference plate is used to whiten global illumination. The detected interreflections represent local variation of illumination.