A Local Active Contour Model for Image Segmentation with Intensity Inhomogeneity

A novel locally statistical active contour model (ACM) for image segmentation in the presence of intensity inhomogeneity is presented in this paper. The inhomogeneous objects are modeled as Gaussian distributions of different means and variances, and a moving window is used to map the original image into another domain, where the intensity distributions of inhomogeneous objects are still Gaussian but are better separated. The means of the Gaussian distributions in the transformed domain can be adaptively estimated by multiplying a bias field with the original signal within the window. A statistical energy functional is then defined for each local region, which combines the bias field, the level set function, and the constant approximating the true signal of the corresponding object. Experiments on both synthetic and real images demonstrate the superiority of our proposed algorithm to state-of-the-art and representative methods. Index Terms —Active contour model; level set method; segmentation; intensity inhomogeneity; bias field correction * Corresponding author. Email: [email protected]. K.H. Zhang, L. Zhang and D. Zhang are with the Department of Computing, The Hong Kong Polytechnic University. K.M. Lam is with the Department of Electronic and Information Engineering, The Hong Kong Polytechnic University. A Locally Statistical Active Contour Model for Image Segmentation with Intensity Inhomogeneity