Human action recognition still exists many challenging problems such as different viewpoints, occlusion, lighting conditions, human body size and the speed of action execution, although it has been widely used in different areas. To tackle these challenges, the Kinect depth sensor has been developed to record real time depth sequences, which are insensitive to the color of human clothes and illumination conditions. Many methods on recognizing human action have been reported in the literature such as HON4D, HOPC, RBD and HDG, which use the 4D surface normals, pointclouds, skeleton-based model and depth gradients respectively to capture discriminative information from depth videos or skeleton data. In this research project, the performance of four aforementioned algorithms will be analyzed and evaluated using five benchmark datasets, which cover challenging issues such as noise, change of viewpoints, background clutters and occlusions. We also implemented and improved the HDG algorithm, and applied it in cross-view action recognition using the UWA3D Multiview Activity dataset. Moreover, we used different combinations of individual feature vectors in HDG for performance evaluation. The experimental results show that our improvement of HDG outperforms other three state-of-the-art algorithms for cross-view action recognition.
翻译:人类行动认识仍然存在许多具有挑战性的问题,如不同观点、隔离、照明条件、人体尺寸和行动执行速度等,尽管在不同领域广泛使用。为了应对这些挑战,开发了Kinect深度传感器,以记录实时深度序列,这些序列对服装的颜色和照明条件不敏感。文献中报告了承认人类行动的许多方法,如HON4D、HOPC、RBD和HDG,它们分别使用4D表面正态、点球、基于骨骼的模型和深度梯度,从深度视频或骨骼数据中获取歧视性信息。在这个研究项目中,上述四种算法的性能将使用5个基准数据集加以分析和评估,这些数据集涉及诸如噪音、观点变化、背景斑点和封闭等具有挑战性的问题。我们还实施并改进了HDG算法,并运用UWA3D多视图活动数据集在跨视图行动识别中应用了该算法。此外,我们使用了不同组合的HDG的单个特性矢量来进行绩效评估。实验结果显示我们对HDG的其他动作的交叉认识。