Authentication Watermarkings for Binary Images

Abstract

Data hiding (DH) is a technique used to embed a sequence of bits in a cover image with small visual deterioration and the means to extract it afterwards. Authentication watermarking (AW) techniques use DH to insert particular data into an image, in order to detect later any accidental or malicious alterations in the image, as well as to certify that the image came from the right source. In recent years, some AWs for binary images have been proposed in the literature. The authentication of binary images is necessary in practice, because most scanned and computer-generated document images are binary.This publication describes techniques and theories involved in binary image AW: We describe DH techniques for binary images and analyze which of them are adequate to be used in AWs; analyze the most adequate secret- and public-key cryptographic ciphers for the AWs; describe how to spatially localize the alteration in the image (besides detecting it) without compromising the security; present AWs forJBIG2-compressed binary images; present a reversible AW for binary images; and finally present our conclusions and future research.