Directional detail histogram for content based image retrieval

With the widespread availability of personal computers and the staggering amount of digital imagery available, recent investigation has focused on the storage, query and retrieval of images from large image databases. Methods, which are employed presently, precompute image indices, which are deemed to be statistical representations of image information. Queries of colour, shape, texture, etc., are then performed directly on these indices to find valid images. We propose a new indexing technique which calculates the histogram of the directional detail content in a given image. We apply wavelet theory and multiresolution analysis to extract the directional information from an image. This information is mapped into 3-dimensional vectors and histograms are calculated, allowing image query using colour histogram techniques to be directly applied. Our technique is capable of querying and searching a database for images based on attributes such as smoothness, randomness and horizontal, vertical and diagonal edges at varying resolutions.