MODIFIED CLAHE: AN ADAPTIVE ALGORITHM FOR CONTRAST ENHANCEMENT OF AERIAL, MEDICAL AND UNDERWATER IMAGES

Image enhancement has been an area of active research for decades. Most of the studies are aimed at improving the quality of image for better visualization. Contrast Limited Adaptive Histogram Equalization (CLAHE) is a technique to enhance the visibility of local details of an image by increasing the contrast of local regions. The algorithm is extensively used by various researches for applications in medical imagery. The drawback of CLAHE algorithm is the fact that it is not automatic and needs two input parameters viz., N size of the sub window and CL the clip limit for the method to work. Unfortunately none of the researchers have done the automatic selection of N and CL to make the algorithm suitable for any autonomous system.