Linear conoscopic holography as aid for forensic handwriting expert

Conoscopic holography is a fringe generation method widely used to reconstruct surface profiles with high precision. By means of linear fringe method, it is possible obtaining a depth analysis with resolution better than 1 μm. This depth allows utilizing conoscopic holography also to aid the forensic handwriting expert.In fact manuscripts have 3D characteristics, which can be acquired only with systems having a high level of details in the z dimension. In particular, this peculiarity has been used for analyzing line crossing cases, some of the more controversy during signature association in trials. Sometimes the analysis of the only 3D profile is not sufficient to clearly associate a signature to a specific person. In this article, a method to generate a pressure profile by means of a linear conoscopic holography System, which can identify a person from a template generated by this profile, in a way similar to biometric voice recognition systems is proposed.