关键词: Tsallis, 二维直方图, 图像分割, 阈值, 粒子群优化（PSO）

Abstract: The Tsallis entropy is a recent development in statistical mechanics and it is a new formalism in which a real quantity q was introduced as parameter for physical systems that present long range interactions,long time memories and fractal-type structures.In this paper,we present a thresholding technique based on two-dimensional Tsallis entropy,which was obtained form the two-dimensional histogram which was determined by using the gray value of the pixels and the local average gray value of the pixels.However,its time-consuming computation is often an obstacle in real time application systems.In our method the threshold vector （s,t）,where s is a threshold for pixel intensity and t is another threshold for the local average intensity of pixels,is obtained through a new optimization algorithm,namely,the Particle Swarm Optimization（PSO） algorithm.The effectiveness of the proposed method is demonstrated by using examples from the real-world and synthetic images.

Key words: Tsallis entropy, two-dimensional histogram, image segmentation, thresholding, Particle Swarm Optimization（PSO）