Dynamic contrast enhancement method for digital image display

An enhancement degree controllable histogram equalization (EDCHE) method is developed in this paper. In this method, the drawback of histogram equalization applied to digital video signal, which could produces unrealistic effects in images because it does not have the mechanisms that adjust the degree of enhancement, is overcome. Different to conventional HE, before calculate the accumulated normalized histogram (CDF), a constant is add to the normalized histogram of image. And the degree of contrast enhancement can be controlled by a adjusting the constant. This method has been implemented on a 50-inch Plasma Display Panel (PDP) and the experiment results show that this method enhances the image display contrast quality adaptively and observably and no unrealistic effects can be seen in the panel.