The Sixth Framework Programme

1. Project summary In this project we aim to invent and develop new techniques for the retrieval of figurative images (such as clip art, logos, signs) from large databases. Our techniques will be based on the extraction and matching of perceptually relevant shape features, thereby overcoming many of the limitations of existing methods. This project will develop and evaluate new algorithms for: • Perceptual segmentation of raw images, and grouping of shape elements. • Matching of geometrical patterns representing shape features. • Partial matching: fitting part of one shape with part of another. • Indexing shape features in huge databases of figurative images. • Indexing the relative spatial layout of shape features within these images. The project meets the objectives of the FET programme through a highly-innovative (and hence high-risk) programme to develop novel techniques for shape matching aimed at tackling one of the key problems limiting the effectiveness of current image retrieval techniques. Our project offers the possibility of significant advances at both the scientific and economic level. New in our approach is the primary role of perceptually relevant shape features, the emphasis on the unsolved problem of partial matching, and indexing over layout and shapes rather than over feature vectors. The newly developed algorithms will be experimentally verified in a prototype system, and subjected to rigorous evaluation on databases with independently-validated ground truth. 2. Project objectives espite over a decade of research into content-based image retrieval (CBIR), the task of finding a arious com n Tanase, 2001). Tec iq ly-produced images which incl e eived less attention, even tho e different techniques for effe v ally-produced (Eakins, 2001). • Accurate retrieval and management of such images is of major economic importance. • Figurative images provide an ideal vehicle for the development of improved shape retrieval techniques, which could be applicable to a much wider domain of images. Shape is probably the single most important feature used by human observers to characterize an image-psychological studies (e.g. Biederman, 1987) show that a whole range of familiar objects can be recognized as readily from stylised line drawings as from full-colour natural images. However, the process of automatically extracting image features that characterize these elements has proved remarkably difficult, as illustrated in Fig 1. Professional trademark examiners judge all of the following four images to be similar, because all can be perceived as a triangle enclosing a circle-even though they differ in …