Learning simultaneous adaptive clustering and classification via MOEA

• A simultaneous adaptive clustering and classification learning via MOEA is proposed.
• New clustering objective function is designed, and two objective functions complement with each other.
• The number of clusters can be determined adaptively during the learning process.
• The drawback from clustering/classification learning is used to guide the search.
• We extend it to texture image and SAR image segmentation to show its effectiveness.

Clustering learning and classification learning are two major tasks in pattern recognition. The traditional hybrid clustering and classification algorithms handle them in a sequential way rather than a simultaneous way. Fortunately, multiobjective optimization provides a way to solve this problem. In this paper, an algorithm that learns simultaneous clustering and classification adaptively via multiobjective evolutionary algorithm is proposed. The main idea of this paper is to optimize two objective functions which represent fuzzy cluster connectedness and classification error rate to achieve the goal of simultaneous learning. Firstly, we adopt a graph based representation scheme to encode so that it can generate a set of solutions with different number of clusters in a single run. Then the relationship between clustering and classification is built via the Bayesian theory during the optimization process. The quality of clustering and classification is measured by the objective functions and the feedback drawn from both aspects is used to guide the mutation. At last, a set of nondominated solutions are generated, from which the final Pareto optimal solution is selected by using Adjusted Rand Index. The results on synthetic datasets and real-life datasets demonstrate the rationality and effectiveness of the proposed algorithm. Furthermore, we apply the proposed algorithm to image segmentation including texture images and synthetic aperture radar images, the experimental results show the superiority of the proposed algorithm compared with other five algorithms.