Sketch-based retrieval of drawings using spatial proximity

Currently, there are large collections of drawings from which users can select the desired ones to insert in their documents. However, to locate a particular drawing among thousands is not easy. In our prior work we proposed an approach to index and retrieve vector drawings by content, using topological and geometric information automatically extracted from figures. In this paper, we present a new approach to enrich the topological information by integrating spatial proximity in the topology graph, through the use of weights in adjacency links. Additionally, we developed a web search engine for clip art drawings, where we included the new technique. Experimental evaluation reveals that the use of topological proximity results in better retrieval results than topology alone. However, the increase in precision was not as high as we expected. To understand why, we analyzed sketched queries performed by users in previous experimental sessions and we present here the achieved conclusions.