Orientation radiograms for indexing and identification in image databases

Archival of images in databases, enabling further study with respect to their contents, is at our focus of attention. The major difficulties are i) the processing of a large number of images, ii) that the steadily growing number of images increase the complexity of the pattern recognition problems to be solved. We propose orientation radiograms, to be used as image signatures for shape based queries. These are the projections of a set of orientation decomposed images (here 6) to axes whose directions change synchronously with the orientation bands at hand. The peaks in the radiograms represent long edges or lines which are important for the human when he recognizes or compares images. We present the results of experiments based on approximately 400 images in an application concerning typographic ornament images. Also is presented a comparative study comprising classical moment invariants.