Image contrast enhancement by vector evaluated particle swarm optimization (VEPSO)

Histogram equalization (HE) is a popular technique to enhance the image in terms of image contrast. HE techniques expand the image histogram to an wider available range of gray levels from its narrow range in the original image. The conventional approaches are capable to enhance the contrast but provide limitations like non-uniform brightness distribution, false contouring, lack of edge retention, noise artifacts, etc. This paper presents a vector evaluated particle swarm optimization (VEPSO) approach to HE to avoid the limitations. The presented method is tested with set of low contrast grayscale images from standard database and found to be competitive to the conventional techniques. The comparison of potential of the presented method is drawn in terms of visual as well as objective evaluation against commonly used image quality evaluation metrics.