We describe how video data can be organized and structured so as to fa
cilitate efficient querying. We develop a formal model for video data
and show how spatial data structures, suitably modified, provide an el
egant way of storing such data. We develop algorithms to process vario
us kinds of video queries and show that, in most cases, the complexity
of these algorithms is linear. A prototype system, called the Advance
d Video Information System (AVIS), based on these concepts, has been d
esigned at the University of Maryland.