Digital Watermarking and Stenography via Overlays of Halftone Images

Copyright 2004 Society of Photo-Optical Instrumentation Engineers. This paper was (will be) published in and is made available as an electronic reprint [preprint] with permission of SPIE. Single print or electronic copies for personal use only are allowed. Systematic or multiple reproduction, distribution to multiple locations through an electronic listserver or other electronic means, duplication of any material in this paper for a fee or for commericial purposes, or modification of the content of the pater are all prohibited. By choosing to view or print this document, you agree to all the provisions of the copyright law protecting it.

Recently, several watermarking schemes have been proposed that embed a watermark into two halftone images such that the watermark can be extracted by overlaying these halftone images. The watermark images in these schemes are binary images and the pixels in the two halftone images are correlated or not depending on whether the corresponding pixel in the watermark is on or o.. In these schemes, the watermark is binary and does not contain detailed features. Furthermore, the extracted watermark contains residual patterns from the two images which reduces the fidelity of the extracted watermark image. This paper proposes a watermarking algorithm that addresses these problems. In addition, the proposed scheme admits more general watermark extraction functions and allows embedding of multiple watermark images.

By: Chai Wah Wu, Gerhard Thompson, Mikel Stanich

Published in: SPIE Proceedings, volume 5561, (no 1), pages 152-63 in 2004


This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.


Questions about this service can be mailed to .