Generalization of hue in the RGB cube space

The general formulation of hue is continually being established throughout the study of the RGB (red, green, blue) cube space. This paper proposes a formulation that consists of a forward RGB to hue transform and its inverse for perfect RGB color reproduction. The proposed formulation is defined independently of the saturation and brightness, which can be considered fixed as constants. Our study indicates that the hue angle monotonically changes with the increments and decrements of intensity in the median of RGB channels. Furthermore, the formulation has simplified the hue definitions using median channel as the shift for hue angle. As a result, the forward transform produces a new set of hue angular information which significantly improves the performance of the existing hue models in terms of perceptual uniformity, visual quality and efficiency. The proposed formulation is beneficial to machine vision related studies, essentially the image segmentation and image classifications.