R-Histogram
Yuhang Wang, Fillia S. Makedon · 2003
Representation of relative spatial relations between objects is required in many multimedia database applications. Quantitative representation of spatial relations taking into account shape, size, orientation and distance is often required. This cannot be accomplished by assimilating an object to elementary entities such as the centroid or the minimum bounding rectangle. Thus many authors have proposed numerous representations based on the notion of histograms of angles. However, they can only represent directional relations, but not the topological spatial relations inside and overlap. Moreover, distance information is not explicitly taken into account. To address these issues, we propose in this paper a new histogram representation called R-Histogram that extends the histogram of angles by incorporating both angles and labeled distances. Dissimilarity between images is then defined by the distance between corresponding R-Histograms. A prototype Query By Example (QBE) system using the R-Histogram has been implemented. The effectiveness of our algorithm is demonstrated with experiments on two databases of 2000 synthetic images.