A reliable image segmentation algorithm is proposed in this paper.Based on the assumption that the observed image is the sum of the segmentation image and the irregular corruptive noise
the segmentation image is modeled by a MRF(Markov random field)prior distribution while the observed image is modeled by a contaminated Gaussian distribution.The Bayes formulation is adopted to obtain the conditional distribution of the a posteriori distrbution of the segmentation image conditioned on the observed image
and based on MAP (maximum a posteriori) criterion the segmentation result is then obtained by applying ICM(iterated conditional mode) algorithm to maximize the a posteriori distribution.The algorithm has reliable segmentation result compared to that proposed by Lakshmanan et al .Experimental results are very satisfactory.