Color Image Enhancement Based on Hue Invariability

Hue is an important attribute of color information.Hue invariability is very important to color image enhancement.Normally,people transform the color space of image from RGB to HIS,then enhance the variable I(intensity) only.Because of the transformation between RGB and HIS is very complex,the program will compute for a long time.Therefor a new method of color image enhancement is proposed.After analyzing the simplified model of HIS,it is found that the hue will keep invariant if the R、G、B multiplies or adds same number.So we can generalize the enhancement scheme for grey scale images to color images without transformation of color space.This paper also discusses the gamut problem and its solution.The gamut problem will lead to distortion of color.The method proposed by this article keeps off the transformation between RGB and HIS,so it can obviously simplify the computation.It is very useful in real-time situation.Experiment results have shown that the proposed method works well in enhancing color image,and it's efficient.