Abstract: A novel region based active contours model was proposed to deal with the images with intensity inhomogeneities and weak boundaries．For the proposed model,a new energy function was defined,which consists of a local fitting term and an auxiliary global fitting term．Then,the energy functional was incorporated into a variational level set formulation．Furthermore,we regularized the level set function by using Gaussian filtering to keep it smooth and eliminated the re-initialization．In addition,the proposed model can degrade to a new global CV model．Experiments results show that the proposed model can not only segment images with intensity inhomogeneities and weak boundaries,but also robust to the noise and initial contours．Also,it has high computational efficiency.

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