Abstract. For legal purposes there is a requirement for the validation of signatures and handwritten documents. A helpful method in this respect is the so-called superposed strokes analysis, based on the observation of some characteristics in the writing, such as some letters and their dynamics.

This paper introduces a promising new technique for superposed strokes analysis based on conoscopic holography. Through a non-contact 3D measure a 3D profile is created of the superposed strokes that allows the writing dynamics to be determined, such as, for example, if a stroke was drawn clockwise or counterclockwise.

We propose a 3D analysis by an opto-electronic system, in order to improve the graphology analysis for off-line signature verification.

Keywords: 3D digitizing, conoscopic holography, graphology, superposed strokes analysis

Print publication: Issue 9 (September 2004)
Received 5 January 2004, accepted for publication 27 July 2004
Published 10 August 2004