HCI (hue-chroma-intensity) color model: A robust color representation under illumination changes

Abstract

In this paper, we introduce and propose a new color representation scheme, the HCI color model, and its usage. The HCI color model consists of three channels; hue, chroma, and intensity. Using the dichromatic reflection model, it is proved that hue is robust against illumination effects. Since this new color model is not expanded to a cylindrical form, not only the problem of saturation dependence on the brightness can be avoided, but also the fully saturated achromatic color problem cannot occur. However, there is some risk to specify the coordinates which lie outside the color gamut. In order to prevent this risk, some boundary conditions are defined. Finally, the mixture color model is introduced to enhance the accuracy of color expression. To prove the usefulness and the validity of the HCI color model, several experiments and analysis of the results are presented and demonstrated.