Audio-visual event detection using duration dependent input output Markov models

Analysis of audio-visual data and detection of semantic events with spatio-temporal support is a challenging multimedia understanding problem. The difficulty lies in the gap that exists between low level media features and high level semantic concept. We introduce a duration dependent input output Markov model (DDIOMM) to detect events based on multiple modalities. The DDIOMM combines the ability to model non-exponential duration densities with the mapping of input sequences to output sequences. We test the DDIOMM by modelling the audio-visual event explosion. We compare the detection performance of the DDIOMM with the IOMM as well as the HMM. Experiments reveal that modeling of duration improves detection performance.