Range Limited Peak-Separate Fuzzy Histogram Equalization for image contrast enhancement

Histogram equalization is a well-known technique for enhancing image contrast for its simplicity and effectiveness. However, the existing approaches to this technique may change the contrast so sharply that it is unsuitable to be implemented in consumer electronics. In this paper, we propose a novel histogram equalization method referred to as Range Limited Peak-Separate Fuzzy Histogram Equalization (RLPSFHE), which aims to gain a good trade-off between mean-brightness preservation and contrast enhancement, so that it can be applied in consumer electronics. In the RLPSFHE, fuzzy statistics is applied to deal with digital images for their representation, and a set of peaks is calculated from the crisp fuzzy histogram, which is a set of points for separation. Since then, the input fuzzy histogram can be divided into several segments with those points of peak. After that, an intensity factor is employed to control the intension of brightness preservation when a range limited method is used to process each sub-histogram, the experimental results show that the RLPSFHE can achieve a better trade-off between mean-preservation and contrast enhancement.