Contours smoothing for non-occluded planar shapes description

In this paper, we present some preliminary results obtained with the MSGPR method in the context of pattern recognition: this new method is based on the analysis of closed contour of planar objects. The contour C₀ of a planar object is parameterised by its curvilinear abscissa u and separated into two signals x(u) and y(u) corresponding to its coordinates x and y. These signals are then filtered with a Gaussian low-pass filter. The size of the sub-consequent contour C_σ is then adjusted so that it has the same size as the original contour C₀. Then the contour C_GC(σ) thus obtained and the original contour C₀ yield intersection points that give intersection points map (IPM) which is used to characterise the pattern. By construction, this method is invariant under translation. The results of analysis have shown its invariance under rotation and its resistance against scale change for a large range of scaling. It is a fast and simple algorithm that can be successfully applied in the context of pattern recognition dedicated to planar non-occluded objects. The application of this method in the research of a query pattern in a database has given very encouraging results.