Incremental learning-based visual tracking with weighted discriminative dictionaries

Existing sparse representation-based visual tracking methods detect the target positions by minimizing the reconstruction error. However, due to complex background, illumination change, and occlusion problems, these methods are difficult to locate the target properly. In this article, we propose a novel visual tracking method based on weighted discriminative dictionaries and a pyramidal feature selection strategy. First, we utilize color features and texture features of the training samples to obtain multiple discriminative dictionaries. Then, we use the position information of those samples to assign weights to the base vectors in dictionaries. For robust visual tracking, we propose a pyramidal sparse feature selection strategy where the weights of base vectors and reconstruction errors in different feature are integrated together to get the best target regions. At the same time, we measure feature reliability to dynamically adjust the weights of different features. In addition, we introduce a scenario-aware mechanism and an incremental dictionary update method based on noise energy analysis. Comparison experiments show that the proposed algorithm outperforms several state-of-the-art methods, and useful quantitative and qualitative analyses are also carried out

IR-capsule: two-stream network for face forgery detection.

Background: With the emergence of deep learning, generating forged images or videos has become much easier in recent years. Face forgery detection, as a way to detect forgery, is an important topic in digital media forensics. Despite previous works having made remarkable progress, the spatial relationships of each part of the face that has significant forgery clues are seldom explored. Methods: To overcome this shortcoming, a two-stream face forgery detection network that fuses Inception ResNet stream and capsule network stream (IR-Capsule) is proposed in this paper, which can learn both conventional facial features and hierarchical pose relationships and angle features between different parts of the face. Furthermore, part of the Inception ResNet V1 model pre-trained on the VGGFACE2 dataset is utilized as an initial feature extractor to reduce overfitting and training time, and a modified capsule loss is proposed for the IR-Capsule network. Results: Experimental results on the challenging FaceForensics++ benchmark show that the proposed IR-Capsule improves accuracy by more than 3% compared with several recently published methods. Conclusions: The proposed method provides a new solution for face forgery detection, which has outperformed a few state-of-the-art models