Efficient Extraction and Representation of Spatial Information from Video Data

Vast amounts of video data are available on the weband are being generated daily using surveillancecameras or other sources. Being able to efficientlyanalyse and process this data is essential for a numberof different applications. We want to be ableto efficiently detect activities in these videos or beable to extract and store essential information containedin these videos for future use and easy searchand access. Cohn et al. (2012) proposed a comprehensiverepresentation of spatial features that canbe efficiently extracted from video and used forthese purposes. In this paper, we present a modifiedversion of this approach that is equally efficientand allows us to extract spatial informationwith much higher accuracy than previously possible.We present efficient algorithms both for extractingand storing spatial information from video,as well as for processing this information in orderto obtain useful spatial features. We evaluate ourapproach and demonstrate that the extracted spatialinformation is considerably more accurate than thatobtained from existing approaches.