Novel histogram processing for colour image enhancement

In practice, the histogram equalization often produces images with unnatural appearances and visually disturbing artefacts. One of the reasons for these unwanted effects is that the histogram equalization attempts to force the output image to have a uniform pixel distribution regardless of what the original image´s pixel distribution may be. In this paper, we present a novel histogram processing algorithm which takes into account the original image´s pixel distribution in the equalization process. The method uses a single parameter to control the degree of contrast enhancement to ensure that the output have an enhanced appearance which is also faithful to that of the original image and is free of unwanted visually disturbing artefacts. We first develop the algorithm for the luminance channel and then extend the method to the colour components. We present experimental results to demonstrate the better performances of our new method over established methods in the literature.