Uncertainties can occur in any transformation and imaging technique such as flat EEG. Therefore, fuzzy set theory is used to model the uncertainties. In this paper, the flat-EEG images are enhanced based on the type-2 fuzzy set. The type-2 fuzzy set considers the fuzziness in the membership functions, and the upper and lower membership values are calculated. Moreover, a new membership function is obtained by using t-conorm to enhance the images. The experimental results show that the method gives better results than the non-fuzzy method. [ABSTRACT FROM AUTHOR]