video databases what are it uses? –sports –surveillance how do we query it? –mosaic-based...

Video Databases• What are it uses?

– Sports– Surveillance

• How do we query it?– Mosaic-based Query Language

A Mosaic-based Query Language for Video Databases

• A visual language for content-based querying of video shots

• Mosaics allow the representation of the entire content of a shot in a single image

• The language enables the specification of queries, encompassing both motion and visual features

• Features of camera, object, and background contained in a shot, which are possible query attributes, are all condensed into the mosaic image

• The main idea underlying mosaic images of video shots is that of providing a synthetic representation of the shot’s content by eliminating redundancy:

• Mosaic images provide a comprehensive overview of different camera movements occurred during the shot. Different combinations of pan, tilt, zoom, and rotation, result in different shapes for mosaic images

• The primitive components of our visual query language include:– camera frame– object reference– Background

• There are two operators to form sentences or queries:– Concatenation– Composition

• Prototype of user interface is written in Java and creates a XML-query:

• Previous queries can be re-edited and refined• Shots from query results can be used as starting points

for a new query