Fast Event Detection in MPEG Video

Many video applications, such as surveillance systems are continuously increasing and the amount of processed and stored data has risen exponentially. In order to manage efficiently this video information, motion detection is necessary. This feature is required to analyze, organize and store compressed video. In this paper, we present an effective video event detection method, which uses information embedded in the MPEG-4 bit stream to detect true motion in the scenario, avoiding other features like scene cuts and camera translation, zooming, pan, tilt and oscillations These events can be detected very fast and with low computational complexity, as only few parameters of the compressed data are processed. This algorithm mainly relies on the amount of signal variation of AC coefficients, between co-localized intra coded blocks, and the amount of motion compensated coded macroblocks within inter coded frames. Our results have shown that this algorithm can perform not only accurate motion detection, but also identifying false motion due to camera movements.