Indexing of technical line drawings based on F-signatures

We propose a method for indexing technical drawings. Our features are based on the notion of F-signature, which is a particular histogram of forces. The force histogram has low time complexity and describes a signature which is invariant to scaling, translation, symmetry and rotation. This article presents a new application of such signatures in the field of document analysis, and tests different characteristics of the F-signatures, like their sensitivity to the shape of the objects and to noise. Finally, experimental results show the effectiveness of such an approach. A brief overview of pattern recognition approaches dedicated to technical document indexing is given. The notions of histogram of forces and of its properties are presented.