Aiming at the character of visible image,a new contrast intensifying technique is presented using segmented histogram nonlinear extension.For the image being intensified effectively,the specific image is cut into three parts (target area,transition area and background area).Based on the characteristic of each part,different gray scale transforms are designed to carry out image nonlinear transform (the uneven transverse extension of the image histogram).Then using the gray-level redundancy equilibrating.The result shows that the technique can increase the contrast and suppressing the background.