Enhancing sketch-based sport video retrieval by suggesting relevant motion paths

Searching for scenes in team sport videos is a task that recurs very often in game analysis and other related activities performed by coaches. In most cases, queries are formulated on the basis of specific motion characteristics the user remembers from the video. Providing sketching interfaces for graphically specifying query input is thus a very natural user interaction for a retrieval application. However, the quality of the query (the sketch) heavily depends on the memory of the user and her ability to accurately formulate the intended search query by transforming this 3D memory of the known item(s) into a 2D sketch query. In this paper, we present an auto-suggest search feature that harnesses spatiotemporal data of team sport videos to suggest potential directions containing relevant data during the formulation of a sketch-based motion query. Users can intuitively select the direction of the desired motion query on-the-fly using the displayed visual clues, thus relaxing the need for relying heavily on memory to formulate the query. At the same time, this significantly enhances the accuracy of the results and the speed at which they appear. A first evaluation has shown the effectiveness and efficiency of our approach.