Aggregation pheromone density based change detection in remotely sensed images

Ants, bees and other social insects deposit pheromone (a type of chemical) in order to communicate between the members of their community. Pheromone that causes clumping or clustering behavior in a species and brings individuals into a closer proximity is called aggregation pheromone. This article presents a novel method for change detection in remotely sensed images considering the aggregation behavior of ants. Change detection is viewed as a segmentation problem where changed and unchanged regions are segmented out via clustering. At each location of data point, representing a pixel, an ant is placed; and the ants are allowed to move in the search space to find out the points with higher pheromone density. The movement of an ant is governed by the amount of pheromone deposited at different points of the search space. More the deposited pheromone, more is the aggregation of ants. This leads to the formation of homogenous groups of data. Evaluation on two multitemporal remote sensing images establishes the effectiveness of the proposed algorithm over an existing thresholding algorithm.