A Framework for Sub-Window Shot Detection

Browsing a digital video library can be very tedious especially with an ever expanding collection of multimedia material. We present a novel framework for extracting sub-window shots from MPEG encoded news video with the expectation that this will be another tool that can be used by retrieval systems. Sub-windows shots are also useful for tying in relevant material from multiple video sources. The system makes use of Macroblock parameters to extract visual features, which are then combined to identify possible sub-windows in individual frames. The identified sub-widows are then filtered by a non-linear Spatial-Temporal filter to produce sub-window shots. By working only on compressed domain information, this system avoids full frame decoding of MPEG sequences and hence achieves high speeds of up to 11 times real time.