Ali Zarei - Department of Computer and Information Technology Faculty of Engineering, University of Kurdistan Sanandaj, Iran
Milad Shirmohamadi - Faculty of Engineering, Azad University Hamedan, Iran
Fardin Akhlagian Tab - Assistant professor, University of Kurdistan Sanandaj, Iran

Histogram equalization (HE) is an effective image enhancing technique but in some conditions, the output is an image without natural brightness. In this paper, provided a new method to increase the image contrast based on histogram of image. In the proposed method, firstly histogram of the image is divided into two fuzzy sets, on a middle basis of the intensity of the image colors. By calculating the membership function for each level, new values of the levels are calculated by value of their membership function. Comparing the results of our method and other techniques which have earlier been carried out on low contrast images; it was found that the result of our proposed method is better than other methods.

Contrast enhancement, histogram, membership, fuzzy