In many computer vision applications, one image can be represented by multiple heterogeneous features from different views, most of them commonly locate in high-dimensional space. These features can reflect different characteristics of one same object, they contain compatible and complementary information among each other. How to construct an uniform low-dimensional embedding features which represent useful information of multi-view features is still an important and urgent issue to be solved. Therefore, we propose a multi-view fusion method via tensor learning and gradient descent (MvF-TG) in this paper. MvF-TG reconstructs a lowdimensional mapping subspace of each object by utilizing its k nearest neighbors, which preserves the underlying neighborhood structure of the original local manifold. The new method can effectively exploit the spatial correlation information from the multi-view features by tensor learning. Furthermore, the method constructs a gradient descent optimization model to generate the better unified low dimensional embedding. The proposed method is compared with several single-view and multi-view dimensional reduction methods in these indicators of P, R, MAP and F-measure. In the retrieval experiments, the P values of the newmethod respectively are 86.80%, 52.00%, 68.56% and 78.80% on datasets of Corel1k, Corel5k, Corel10k and Holidays. In the classification experiments, the mean accuracies of it respectively are 47.94% and 87.58% on datasets of Caltech101 and Coil. These values are higher than those obtained by other comparison methods, various evaluations based on the applications of image classification and retrieval demonstrates the effectiveness of our proposed method on multi-view feature fusion dimension reduction.

Current research in hyperspectral anomaly detection often incorporates low-rank (LR) or total variation (TV) priors to encode the background matrix. However, applying such regularizers to the detection model increases the computational burden. In this letter, we propose a subspace transformation learning-based anomaly detector (termed STLAD). In STLAD, we employ an orthogonal transformation to represent the background in its subspace, where both the background and the transformation share spatial smoothness prior and approximate sparsity properties based on carefully selected basis vectors. By leveraging this background characterization, the anomaly component can be effectively described using the ℓ2,1 mixed norm. To solve the STLAD model, we design an alternating direction method of multipliers (ADMM) with guaranteed convergence. Experiments conducted on benchmark hyperspectral datasets demonstrate that STLAD outperforms several state-of-the-art anomaly detection methods. The demo of STLAD will be publicly available at: https://github.com/XiangfeiShen/STLAD.