Matching of graphical symbols in line-drawing images using angular signature information

Abstract.

In this paper, a method for matching complex objects in line-drawings is presented. Our approach is based on the notion of $\mathcal{F}$-signatures, which are a special kind of histogram of forces [17,19,28]. Such histograms have low time complexity and describe signatures that are invariant to fundamental geometrical transformations such as scaling, translation, symmetry, and rotation. This article presents a new application of this notion in the field of symbol identification and recognition. To improve the efficiency of matching, we propose using an approximation of the $\mathcal{F}$-signature from Fourier series and the associated matching.