Space-Time Interest PointsIvan Laptev and Tony LindebergIn Proc. ICCV 2003, Nice, France, pp.I:432-439.AbstractLocal image features or interest points provide compact and abstract representations of patterns in the image. In this paper we propose to extend the notion of spatial interest points into the spatio-temporal domain and argue that the resulting features often correspond to the interesting events in video and can be used for the compact representation of video data as well as for its interpretation.To detect spatio-temporal events, we build on the idea of the Harris and Förstner interest point operators and detect local structures in space-time where the image values have significant local variations in both space and time. We then estimate the spatio-temporal extents of the detected events and compute their scale-invariant spatio-temporal descriptors. Using such descriptors we classify events and construct video representation in terms of labeled space-time points. On the problem of human motion analysis we illustrate how the proposed method enables the detection of walking people in scenes with occlusions and dynamic backgrounds. PDF: (1.0Mb)
Related project: Recognition of human actions Related publications: (Interest point detection and scale selection in space-time) (Velocity-adaptation of spatio-temporal receptive fields for direct recognition of activities: An experimental study) (Time-recursive velocity-adapted spatio-temporal scale-space filters) (Linear spatio-temporal scale-space) (Separable scale-space with causal time direction) (Automatic selection of temporal scales in time-causal scale-space) (Monograph on scale-space theory) |