Retrieval of hand-drawn sketches with partial matching

Sketching is a natural way of input that provides an effective means of illustration. A sketch consists of multiple strokes that can be captured by pen-based devices to be stored in a database for future retrieval. In our prior work, we proposed a sketch retrieval method that is suitable for whole matching. However, the problem gets complicated if the retrieval is performed for partially matched sketches. In this paper, we propose a method to solve the partial matching problem for retrieving sketches. In the matching stage, the score is first computed by considering the stroke feature similarity alone. For a sketch consisted of multiple strokes, spatial relations between every pair of strokes (bistroke) can be used together with the bistroke features for finding the correspondence to further improve the retrieval performance. A potential application of sketch retrieval for partial matching is to retrieve materials from the lecture notes for reviewing without the trouble of describing it using keywords.