JSE_V7_N1_RP4 Seetharama Prasad Kolluri Raju Ch Venkata Narayana Journal on Software Engineering 2230 – 7168 7 1 25 34 Image Segmentation, Threshold, Fuzzy measure, Type-I fuzzy, Type-II Fuzzy, Ultrafuzziness In this paper, a study on fuzzy membership functions for image segmentation using ultrafuzziness is conducted. In this work, Tizhoosh membership function which is totally supervised, Huang and Wang membership function and S-function are considered. This work is an improvement of an existing work of Tizhoosh. Each membership function has its own merits and demerits in the computation process. Using fuzzy logic concepts, the problems involved in finding the minimum/maximum of a entropy criterion function are avoided. We attempt to make it clear that identifying the better membership function to assign the fuzzy membership grade to every pixel in the image, for optimum image segmentation using ultrafuzziness. For low contrast images contrast enhancement is assumed. Experimental results demonstrate a quantitative improvement with S-function over other two other functions. July - September 2012 Copyright © 2012 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1965