Shape representation for image retrieval

akhencha I hbriand} @ireste.fr In the domain of the content-based image retrieval, the user formulates his queries from both visual and textual descriptions. In the sequel, we will only dwell on one of the most important visual features, namely the shape feature. The shape feature is essential as it corresponds to region of interest in images. Consequently, the shape representation is fundamental. This description must be compact and accurate, and it must own properties of invariance to several geometric transformations. After presenting several shape representations, we present the two complementary methods implemented in our prototype. The first one is an existing well-known approach, Freeman code, and the second one is an adaptation of a famous approach, Fourier theory. Simulations allow us to compare our results with results obtained under MATLAB, a powerful mathematical software, and to validate the proposed method.