Adjustable weighting image contrast enhancement algorithm and its implementation

Image enhancement is one of the most important techniques in digital imaging processing fields. Traditional global histogram equalization usually causes excessive contrast enhancement while local histogram equalization may cause block effect. To overcome these problems, a new method for image contrast enhancement is developed. The novelty is that the weighted average of histogram equalization and exponential transformation are combined and the level of the contrast improvement is adjustable by changing the weighting coefficients. The proposed algorithm not only achieved adjustable contrast enhancement, for color image, it also weakened the situation of lacking color due to the risen of intensity, thus increasing the image saturation. Experimental results show that the proposed algorithm has good performance on enhancing contrast and color for a majority of images mostly taken by the authors.