优化端元提取方法的高光谱混合像元分解

Optimization of Endmember Extraction in Mixed Pixel Unmixing in Hyperspectral Images

高光谱图像的混合像元分解将原始图像分解为多种纯净地物及相应的丰度,端元提取是混合像元分解的关键技术.针对传统算法计算速度慢、搜索范围较大的特点,基于改进的ICA (independent component analysis)算法以及优化的候选端元判断方法,提出了一种优化的混合像元分解方法.首先使用改进的算法优化端元提取方法;然后利用相邻像素的光谱特征和空间特征信息,结合并行算法对候选端元进行优化;最后利用真实的高光谱数据对该方法的性能进行了验证.验证结果表明:该方法能有效提高端元提取精度,降低复杂度,与经典的端元提取算法N-FINDER相比,准确度提高了3.55%,解混后得到的地物分类精度有了明显改善(总体分类精度提高了2.88%).

Hyperspectral uamixing is a process for unmixing the mixed pixels of a hyperspectral image composedof several substances and their corresponding proportions. Extracting endmembers is a major problem inhyperspectral unmixing. Owing to the goal of achieving a large search range for the endmembers, the efficiencyof the traditional algorithm is usually low. Based on an improved ICA（ independent component analysis）andoptimized endmember extraction method, an improved method of unmixing was proposed. Firstly, ndmemberextraction was optimized by means of an optimized FastICA algorithm. Thereafter, spatial information andspectral information were considered and combined into a multi-core parallel processing to optimize the candidateendmembers. Lastly, the performance of the proposed algorithm was verified using real hyperspectral data. Themethod was shown to overcome the shortcomings of the traditional method and obtain more accurateendmembers. In particular, compared to the accuracy of the traditional N-FINDER method, the accuracy of theextracted endmembers increases by 3.55%. The object classification accuracy also improves immensely, and theoverall classification accuracy is increased by 2.88%.