Abstract: A novel region_based active contours model is proposed to deal with the images with intensity inhomogeneities and weak boundaries．For the proposed model,new global force and local force are defined,which compose a hybrid energy functional．Then,the energy functional is incorporated into a variational level set formulation．Furthermore,we regularize the level set function by using Gaussian filtering to keep it smooth and eliminate the re-initialization．In addition,the proposed model can degrade to a new global CV model．Experiment results show that the proposed model can not only segment images with intensity inhomogeneities and weak boundaries,but also robust to the noise,initial contours．And,it has high computational efficiency.

Key words: Image segmentation,Active contours model,Intensity inhomogeneities,Initial contours,Noise