A novel color image contrast enhancement algorithm using saturation-lightness combined stretching in the HSL color space for AMOLED applications

A novel color image contrast enhancement algorithm for active-matrix organic light-emitting diode (AMOLED) applications is presented in this paper. The contrast of the color image is enhanced by using saturation-lightness combined stretching in the Hue-Saturation-Lightness (HSL) color space. Without statistic analysis and complex computation such as trigonometric function, the proposed algorithm is simple and efficient, hence it is suitable for mobile AMOLED applications. Moreover, the average execution time of the proposed algorithm is shorter than the conventional histogram equalization (HE), indicating that our algorithm is faster and can be applied to video contrast enhancement in real-time system. Furthermore, one self-adaptive parameter and three feedback parameters are also employed to optimize the contrast enhancement performance for different kinds of images. The proposed algorithm has been verified on software and implemented on field programmable gate array (FPGA).