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Mathematical Problems in Engineering
Volume 2014, Article ID 182415, 8 pages
http://dx.doi.org/10.1155/2014/182415
Research Article

Active Contour Driven by Local Region Statistics and Maximum A Posteriori Probability for Medical Image Segmentation

College of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China

Received 14 March 2014; Revised 11 June 2014; Accepted 23 June 2014; Published 8 July 2014

Academic Editor: Jun Jiang

Copyright © 2014 Xiaoliang Jiang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper presents a novel active contour model in a variational level set formulation for simultaneous segmentation and bias field estimation of medical images. An energy function is formulated based on improved Kullback-Leibler distance (KLD) with likelihood ratio. According to the additive model of images with intensity inhomogeneity, we characterize the statistics of image intensities belonging to each different object in local regions as Gaussian distributions with different means and variances. Then, we use the Gaussian distribution with bias field as a local region descriptor in level set formulation for segmentation and bias field correction of the images with inhomogeneous intensities. Therefore, image segmentation and bias field estimation are simultaneously achieved by minimizing the level set formulation. Experimental results demonstrate desirable performance of the proposed method for different medical images with weak boundaries and noise.