%0 Journal Article %T Affine-Invariant Feature Extraction for Activity Recognition %A Samy Sadek %A Ayoub Al-Hamadi %A Gerald Krell %A Bernd Michaelis %J ISRN Machine Vision %D 2013 %R 10.1155/2013/215195 %X We propose an innovative approach for human activity recognition based on affine-invariant shape representation and SVM-based feature classification. In this approach, a compact computationally efficient affine-invariant representation of action shapes is developed by using affine moment invariants. Dynamic affine invariants are derived from the 3D spatiotemporal action volume and the average image created from the 3D volume and classified by an SVM classifier. On two standard benchmark action datasets (KTH and Weizmann datasets), the approach yields promising results that compare favorably with those previously reported in the literature, while maintaining real-time performance. 1. Introduction Visual recognition and interpretation of human-induced actions and events are among the most active research areas in computer vision, pattern recognition, and image understanding communities [1]. Although a great deal of progress has been made in automatic recognition of human actions during the last two decades, the approaches proposed in the literature remain limited in their ability. This leads to a need for much research work to be conducted to address the ongoing challenges and develop more efficient approaches. It is clear that developing good algorithms for solving the problem of human action recognition would yield huge potential for a large number of potential applications, for example, the search and the structuring of large video archives, human-computer interaction, video surveillance, gesture recognition, and robot learning and control. In fact, the nonrigid nature of human body and clothes in video sequences, resulting from drastic illumination changes, changing in pose, and erratic motion patterns, presents the grand challenge to human detection and action recognition. In addition, while the real-time performance is a major concern in computer vision, especially for embedded computer vision systems, the majority of state-of-the-art human action recognition systems often employ sophisticated feature extraction and learning techniques, creating a barrier to the real-time performance of these systems. This suggests a trade-off between accuracy and real-time performance. The remainder of this paper commences by briefly reviewing the most relevant literature in this area of human action recognition in Section 2. Then, in Section 3, we describe the details of the proposed method for action recognition. The experimental results corroborating the proposed method effectiveness are presented and analyzed in Section 4. Finally, in Section 5, we conclude and %U http://www.hindawi.com/journals/isrn.machine.vision/2013/215195/