Linear and Non-linear Contrast Enhancement Image

This paper attempts to undertake the study two types of the contrast enhancement techniques, linear contrast techniques and non-linear contrast techniques. In linear contrast techniques applying three methods, Max-Min contrast method, Percentage contrast method and Piecewise contrast technique. Non-linear contrast techniques applying four contrast methods, Histogram equalization method, Adaptive histogram equalization method, Homomorphic Filter method and Unsharpe Mask. in the Homomorphic Filter method applying by using two type of filter, Low Pass Filter(LPF)and High Pass Filter(HPF).this applying to choose the base guesses for contrast enhancement image.