New human action recognition scheme with geometrical feature representation and invariant discretization for video surveillance

Human action recognition is an active research area in computer vision because of its immense application in the field of video surveillance, video retrieval, security systems, video indexing and human computer interaction. Action recognition is classified as the time varying feature data generated by human under different viewpoint that aims to build mapping between dynamic image information and semantic understanding. Although a great deal of progress has been made in recognition of human actions during last two decades, few proposed approaches in literature are reported. This leads to a need for much research works to be conducted in addressing on going challenges leading to developing more efficient approaches to solve human action recognition. Feature extraction is the main tasks in action recognition that represents the core of any action recognition procedure. The process of feature extraction involves transforming the input data that describe the shape of a segmented silhouette of a moving person into the set of represented features of action poses. In video surveillance, global moment invariant based on Geometrical Moment Invariant (GMI) is widely used in human action recognition. However, there are many drawbacks of GMI such that it lack of granular interpretation of the invariants relative to the shape. Consequently, the representation of features has not been standardized. Hence, this study proposes a new scheme of human action recognition (HAR) with geometrical moment invariants for feature extraction and supervised invariant discretization in identifying actions uniqueness in video sequencing. The proposed scheme is tested using IXMAS dataset in video sequence that has non rigid nature of human poses that resulting from drastic illumination changes, changing in pose and erratic motion patterns. The invarianceness of the proposed scheme is validated based on the intra-class and inter-class analysis. The result of the proposed scheme yields better performance in action recognition compared to the conventional scheme with an average of more than 99% accuracy while preserving the shape of the human actions in video images

A semantic concept for the mapping of low-level analysis data to high-level scene descriptions

Zusammen mit dem wachsenden Bedarf an Sicherheit wird eine zunehmende Menge an Überwachungsinhalten geschaffen. Um eine schnelle und zuverlässige Suche in den Aufnahmen hunderter oder tausender in einer einzelnenEinrichtung installierten Überwachungssensoren zu ermöglichen, istdie Indizierung dieses Inhalts im Voraus unentbehrlich. Zu diesem Zweckermöglicht das Konzept des Smart Indexing & Retrieval (SIR) durch dieErzeugung von high-level Metadaten kosteneffiziente Suchen. Da es immerschwieriger wird, diese Daten manuell mit annehmbarem Zeit- und Kostenaufwandzu generieren, muss die Erzeugung dieser Metadaten auf Basis vonlow-level Analysedaten automatisch erfolgen.Während bisherige Ansätze stark domänenabhängig sind, wird in dieserArbeit ein generisches Konzept für die Abbildung der Ergebnisse von lowlevelAnalysedaten auf semantische Szenenbeschreibungen präsentiert. Diekonstituierenden Elemente dieses Ansatzes und die ihnen zugrunde liegendenBegriffe werden vorgestellt, und eine Einführung in ihre Anwendungwird gegeben. Der Hauptbeitrag des präsentierten Ansatzes sind dessen Allgemeingültigkeit und die frühe Stufe, auf der der Schritt von der low-levelauf die high-level Repräsentation vorgenommen wird. Dieses Schließen in derMetadatendomäne wird in kleinen Zeitfenstern durchgeführt, während dasSchließen auf komplexeren Szenen in der semantischen Domäne ausgeführtwird. Durch die Verwendung dieses Ansatzes ist sogar eine unbeaufsichtigteSelbstbewertung der Analyseergebnisse möglich

View-Invariant Representation And Learning Of Human Action

Automatically understanding human actions from video sequences is a very challenging problem. This involves the extraction of relevant visual information from a video sequence, representation of that information in a suitable form, and interpretation of visual information for the purpose of recognition and learning. We first present a view-invariant representation of action consisting of dynamic instants and intervals, which is computed using spatiotemporal curvature of a trajectory. This representation is then used by our system to learn human actions without any training. The system automatically segments video into individual actions, and computes a view-invariant representation for each action. The system is able to incrementally, learn different actions starting with no model. It is able to discover different instances of the same action performed by different people, and in different viewpoints. In order to validate our approach, we present results on video clips in which roughly 50 actions were performed by five different people in different viewpoints. Our system performed impressively by correctly interpreting most actions