I. Introduction
Color provides useful and important information for object detection, tracking, and recognition, image (or video) segmentation, indexing and retrieval, etc. [1]–[15]. Color constancy algorithms [13], [14] and color histogram techniques [5], [10]–[12], for example, provide efficient tools for indexing in a large image database or for object recognition under varying lighting conditions. Different color spaces (or color models) possess different characteristics and have been applied for different visual tasks. For instance, the HSV color space and the color space were demonstrated effective for face detection [2], [3], and the modified color space was chosen for image segmentation [7]. Recently, a selection and fusion scheme of multiple color models was investigated and applied for feature detection in images [15].