Analysis of Color Contrast Enhancement Techniques

Image enhancement methods are widely used to improve the quality of image by improving its appearance. Usually the images taken by digital cameras are different from the original true color image in terms of color and brightness of the scene captured. Various factors like non uniform illumination, color of ambient light, low or high contrast, and over exposure or under exposure of some specific regions may leads to poor contrast which is annoying to human visual system. Thus, enhancement methods are required for color images. In this paper comparative analysis of various color contrast enhancement techniques for such non uniform illumination images is presented. The performance of spatial domain contrast limited adaptive histogram equalization method is compared with Color contrast enhancement using scaling the DCT coefficient method in compressed domain, For comparing the performance, mean square error and SNR used as parameters. The method is tested on various types of poor illumination color images from different environment.