Abstract: Most of classical active contour models only have advantages on some ways,however they can’t deal with complex images.So the paper proposed a kind of segmentation model with multiple characters.This paper introduced difference image and took the BGFRLS model of difference image as global control of model.In addition,to avoid re-initialization of level set function and shorten the computational time,this paper introduced the penalization function in Li method.Furthermore,to decrease regulation parameters,the self-adaption weight between global control term and local control term was used in place of constant weight.Through these improvements,our method has some advantages as follows.First,the method has the global segmentation character.Second,by means of introducing the difference image,our method is able to process the image with intensity inhomogeneity and detect the weak edge.Third,ours model is robust to image noise.Ours experiments demonstrate that the proposed method is indeed able to segment the images with intensity inhomogeneity,and is able to detect the weak edge.In addition,it has global segmentation character and robustness.

Key words: Image segmentation,Difference image,Intensity inhomogeneity,Global segmentation,Robustness