Maximum cross entropy could obtain good segmental result in the use of the image segmentation.But it needed a lot of computational time which limited its application.On the basis of discussing the elementary principles and features of PSO(Particle Swarm Optimization)algorithms,how to apply PSO algorithms in the selection of image thresholds was discussed and the detail procedures were described.The experimental results showed that the PSO not only realized the right image segmentation but also improved the ...