Fusion of circulant singular spectrum analysis and multiscale local ternary patterns for effective spectral-spatial feature extraction and small sample hyperspectral image classification.

Hyperspectral images (HSIs) contain rich spectral and spatial information, motivating the development of a novel circulant singular spectrum analysis (CiSSA) and multiscale local ternary pattern fusion method for joint spectral-spatial feature extraction and classification. Due to the high dimensionality and redundancy in HSIs, principal component analysis (PCA) is used during preprocessing to reduce dimensionality and enhance computational efficiency. CiSSA is then applied to the PCA-reduced images for robust spatial pattern extraction via circulant matrix decomposition. The spatial features are combined with the global spectral features from PCA to form a unified spectral-spatial feature set (SSFS). Local ternary pattern (LTP) is further applied to the principal components (PCs) to capture local grayscale and rotation-invariant texture features at multiple scales. Finally, the performance of the SSFS and multiscale LTP features is evaluated separately using a support vector machine (SVM), followed by decision-level fusion to combine results from each pipeline based on probability outputs. Experimental results on three popular HSIs show that, under 1% training samples, the proposed method achieves 95.98% accuracy on the Indian Pines dataset, 98.49% on the Pavia University dataset, and 92.28% on the Houston2013 dataset, outperforming several traditional classification methods and state-of-the-art deep learning approaches.