Group activity recognition is a challenging task in complex scenes, which involves the interaction and the relative spatial position relationship of a group of people in the scene. The current group activity recognition methods either lack the fine design or do not take full advantage of interactive features among individuals. Therefore, a network framework based on partitioned attention mechanism and interactive position relationship was proposed, which further considered individual limbs semantic features and explored the relationship between interaction feature similarity and behavior consistency among individuals. Firstly, the original video sequences and optical flow image sequences were used as the input of the network, and a partitioned attention feature module was introduced to refine the limb motion features of individuals. Secondly, the spatial position and interactive distance were taken as individual interaction features. Finally, the individual motion features and spatial position relation features were fused as the features of the group scene undirected graph nodes, and Graph Convolutional Network (GCN) was adopted to further capture the activity interaction in the global scene, thereby recognizing the group activity. Experimental results show that this framework achieves 92.8% and 97.7% recognition accuracy on two group activity recognition datasets (CAD (Collective Activity Dataset) and CAE (Collective Activity Extended Dataset)). Compared with Actor Relationship Graph (ARG) and Confidence Energy Recurrent Network (CERN) on CAD dataset, this framework has the recognition accuracy improved by 1.8 percentage points and 5.6 percentage points respectively. At the same time, the results of ablation experiment show that the proposed algorithm achieves better recognition performance.
For precision control problem of multi-resolution fairing, specific impact of fairing precision caused by fairing scale was studied on the basis of the researches of multi-resolution fairing algorithm and software. Taking semicircular curve as a calibration object, this method revealed the internal relations between selection of fairing scale and fairing precision. The experimental results show that the smaller the fairing scale is, the larger the fairing error is. Secondly, multi-resolution fairing can reflect original curves with less control vertexes and own a strong ability of data compression. Finally, fairing error would be larger at the place of curves with larger curvature.
Concerning the problem that existing blind road recognition method has low recognition rate, simplistic handling, and is easily influenced by light, or shadow, an improved blind road recognition method was proposed. According to the color and texture features of blind road, the algorithm used two segmentation methods respectively including color histogram feature threshold segmentation combined with improved region growing segmentation and fuzzy C-means clustering segmentation for gray level co-occurrence matrix feature. And combined with Canny edge detection and Hough transform algorithm, the proposed algorithm made the blind area separated from the pedestrian area and determines the migration direction for the blind. The experimental results show that the proposed algorithm can segment several kinds of blind road more accurately, detect the boundary and direction of blind road and solve the light and shadow problem partly. It can choose the fastest and the most effective segmentation method adoptively, and can be used in a variety of devices, such as electronic guide ones.