基于聚类识别的极化SAR图像分类

PolSAR Image Classification Based on Discriminative Clustering

该文提出一种基于判别式聚类框架的非监督极化SAR图像分类算法,利用判别式监督分类技术实现非监督聚类。为实现该算法,定义了一个结合softmax回归模型和马尔科夫随机场光滑性约束的能量函数。该模型中,像素类标和分类器均为需要优化的未知变量。该算法从基于目标极化分解和K-Wishart极化统计分布而产生的初始化类标开始,交替迭代优化分类器和类标的能量函数,从而实现对分类器和类标的求解。真实极化SAR数据上的实验结果证明了该算法的有效性和先进性。

This paper presents a novel unsupervised image classification method for Polarimetric Synthetic Aperture Radar （PolSAR） data. The proposed method is based on a discriminative clustering framework that explicitly relies on a discriminative supervised classification technique to perform unsupervised clustering. To implement this idea, an energy function is designed for unsupervised PolSAR image classification by combining a supervised Softmax Regression （SR） model with a Markov Random Field （MRF） smoothness constraint. In this model, both the pixelwise class labels and classifiers are taken as unknown variables to be optimized. Starting from the initialized class labels generated by Cloude-Pottier decomposition and K-Wishart distribution hypothesis, the classifiers and class labels are iteratively optimized by alternately minimizing the energy function with respect to them. Finally, the optimized class labels are taken as the classification result, and the classifiers for different classes are also derived as a side effect. This approach is applied to real PolSAR benchmark data. Extensive experiments justify that the proposed approach can effectively classify the PolSAR image in an unsupervised way and produce higher accuracies than the compared state-of-the-art methods.