Infrared small target detection is widely used for early warning, aircraft monitoring, ship monitoring, and so on, which requires the small target and its background to be represented and modeled effectively to achieve their complete separation. Low-rank sparse decomposition based on the structural features of infrared images has attracted much attention among many algorithms because of its good interpretability. Based on our study, we found some shortcomings in existing baseline methods, such as redundancy of constructing tensors and fixed compromising factors. A self-adaptive low-rank sparse tensor decomposition model for infrared dim small target detection is proposed in this paper. In this model, the entropy of image block is used for fast matching of non-local similar blocks to construct a better sparse tensor for small targets. An adaptive strategy of low-rank sparse tensor decomposition is proposed for different background environments, which adaptively determines the weight coefficient to achieve effective separation of background and small targets in different background environments. Tensor robust principal component analysis (TRPCA) was applied to achieve low-rank sparse tensor decomposition to reconstruct small targets and their backgrounds separately. Sufficient experiments on the various types data sets show that the proposed method is competitive.

Video-based anomalous human behavior detection is widely studied in many fields such as security, medical care, education, and energy. However, there are still some open problems in anomalous behavior detection, such as the large and complicated model is difficult to train, the accuracy of anomalous behavior detection is not high enough and the speed is not fast enough. A spatiotemporal representation learning model is proposed in this paper. Firstly, the spatial-temporal features of the video are extracted by the constructed multi-scale 3D convolutional neural network. Then the scene background is modeled by the high-dimensional mixed Gaussian model and used for anomaly detection. Finally, the accurate position of anomalous behavior in the video data is achieved by calculating the position of the last output feature, that is, the position of the receptive field. The proposed model does not require specific training. Moreover, the proposed method has the advantages of high versatility, fast calculation speed and high detection accuracy. We validated the proposed algorithm on two representative surveillance scene datasets, the Subway and the UCSDSped2. Results show that proposed algorithm has achieved the detection rate of 18 FPS under the condition of common computing resources, and meet the real-time requirements. Moreover, compared the similar methods, the proposed method has achieved the competitive results in both frame-level accuracy and pixel-level accuracy.