Introduction

Abstract

This book discusses techniques to convey side information over a printed media. Those techniques will be referred to as hardcopy communication techniques. The information is modulated over the digital host document and then printed using laser, inkjet printer technologies or other printing/branding processes. In order to recover the information at receiver side, the printed document or branded product is digitalized using either cameras or desk scanners and the resulting digital image is processed to decode the embedded information. The embedded information can be exploited for a variety of applications: document, user and/or content authentication, copyright protection, piracy deterrent, document tracking and other uses.