A multilevel image thresholding segmentation algorithm based on two-dimensional K-L divergence and modified particle swarm optimization

Multilevel im age segmentation is a technique that divides images into multiple homogeneous regions. In order to improve the effectiveness and efficiency of multilevel image thresholding segmentation, we propose a segmentation algorithm based on two-dimensional (2D) Kullback-Leibler (K-L) divergence and modified Particle Swarm Optimization (MPSO). This approach calculates the 2D K-L divergence between an image and its segmented result by adopting 2D histogram as the distribution function, then employs the sum of divergences of different regions as the fitness function of MPSO to seek the optimal thresholds. The proposed 2D K-L divergence improves the accuracy of image segmentation; the MPSO overcomes the drawback of premature convergence of PSO by improving the location update formulation and the global best position of particles, and reduces drastically the time complexity of multilevel thresholding segmentation. Experiments were conducted extensively on the Berkeley Segmentation Dataset and Benchmark (BSDS300), and four performance indices of image segmentation - BDE, PRI, GCE and VOI - were tested. The results show the robustness and effectiveness of the proposed algorithm. (C) 2016 Elsevier B.V. All rights reserved.