Content-based binary image retrieval using the adaptive hierarchical density histogram

This paper proposes a method for binary image retrieval, where the black-and-white image is represented by a novel feature named the adaptive hierarchical density histogram, which exploits the distribution of the image points on a two-dimensional area. This adaptive hierarchical decomposition technique employs the estimation of point density histograms of image regions, which are determined by a pyramidal grid that is recursively updated through the calculation of image geometric centroids. The extracted descriptor combines global and local properties and can be used in variant types of binary image databases. The validity of the introduced method, which demonstrates high accuracy, low computational cost and scalability, is both theoretically and experimentally shown, while comparison with several other prevailing approaches demonstrates its performance.