On the evaluation of human ratings for signature recognition

This work explores the human ability to recognize the authenticity of signatures. We use crowdsourcing to analyze the different factors affecting the performance of humans without Forensic Document Examiner experience. We present different experiments according to different scenarios in which laymen, people without Forensic Document Examiner experience, provide similarity measures related with the perceived authenticity of a given signature. The human responses are used to analyze the performance of humans according to each of the scenarios and main factors. The experiments comprise 240 signatures from BiosecurlD public database and responses from more than 400 people. The results shows the difficulties associated to these tasks, with special attention to the false acceptance of forgeries with rates ranging from 50% to 75%. The results suggest that human recognition abilities in this scenario are strongly dependent on the characteristics considered and the signature at hand. Finally the combination of human ratings clearly outperfoms the individual performance and and a state-of-the-art automatic signature verification system.