Intrinsic signatures for scanned documents forensics : Effect of font shape and size

Recently there has been a great deal of interest in using features intrinsic to a data-generating sensor for the purpose of source identification. Numerous methods have been proposed for different problems related to sensor forensics, such as source camera identification using sensor noise as intrinsic signatures, printer identification using banding artifacts as intrinsic signatures and so on. The goal of our work is to identify the scanner used for generating a scanned (digital) version of a printed (hard-copy) document. In this paper we do extensive analysis of the effect of font shape and size on our recently proposed, texture analysis based intrinsic signatures for scanned documents. Some improvements in these intrinsic signatures are proposed to make them robust to font shapes and sizes.