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 histograms of forces~\cite{matsakis98,matsakis99a,wendling02}. Such histograms have low time complexity and describe signatures which 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 to use an approximation of the $\mathcal{F}$-signature from Fourier series, and the associated matching.