Spatial Layout Representation for Query by Sketch Content Based Image Retrieval

Most content-based image retrieval techniques and systems rely on global features, ignoring the spatial relationships in the image. Other approaches take into account spatial composition but usually focus on iconic or symbolic images. Nevertheless a large class of users' queries request images having regions, or objects, in well-determined spatial arrangements. Within the framework of query-by-sketch image retrieval, we propose a structured spatial layout representation. The approach provides a way to extract the image content starting from basic features and combining them in a higher-level description of spatial layout of components, characterizing the semantics of the scene. We also propose an algorithm that measures a weighted global similarity between a sketched query and a database image.