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Vol.32 No.1 February 1999

New On-Line Surveys and Digital Watermarking

Bob Ellis

February 99 Columns
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The big news this quarter is our new on-line survey, as reported by committee members David Nelson and Laurie Reinhart below. We’ll also take a look at a new technology, digital watermarking, for identifying and protecting digital information, which is particularly applicable to images.

Public Policy Surveys

The Public Policy Committee is pleased to announce the first in a series of on-line surveys. It is our intention to use these surveys to bring a variety of policy issues before SIGGRAPH members and the graphics community and to use the data collected to address issues of importance for proposed legislation and policy.

The first on-line survey is directly related to SIGGRAPH’s first policy white paper entitled “Computer Graphics, Visualization, Imaging and the GII: Technical Challenges and Public Policy Issues” (http://www.siggraph. org/pub-policy/whitepaperGII.html). The first survey is intended to gauge general policy issues and technical issues facing computer graphics professionals. We greatly appreciate your taking the time to fill out this survey in order to serve the graphics community’s needs and bring these important issues before policy-makers.

Our first survey is now available to fill out from our website at www.siggraph. org/pub-policy/ or by going to directly to the survey at The survey should take less than five minutes to complete.

You will notice we have moved our website from http://www.siggraph. org/othercom/pubpolicy.html to http:// We have been adding new content and images to the site and have found it necessary to have our own unique space on the SIGGRAPH web server. We will of course leave up the old HTML documents with dynamic links to reflect the new location(s) of the documents.

Doing on-line surveys has been a strong interest of mine since the Public Policy Committee was formed, even though we cannot do a scientifically correct survey because the respondents are self selected and are not necessarily representative of the sampled population. Let me say just a few words about the plans and timing. The first survey will be active starting sometime in late 1998 or early 1999. We will leave it active until approximately the end of March 1999. Our second survey is already in preparation and will replace the first survey, probably in April 1999. The second survey will be our contribution to the celebration at SIGGRAPH 99 in Los Angeles of the 30th anniversary of the founding of the SIGGRAPH organization. In the survey, we will ask questions about the importance and need for work on a number of computer graphics and related technologies for the future.

I would like to thank Arnie Nelson and committee member David Richard Nelson of Webinsite, Inc. ( for designing the GUI, perl and javascripts necessary for these on-line surveys. I would also like to recognize committee member Laurie Reinhart ( for her participation in the analysis of the data and systems administrator Gary Paxinos for assistance with server configuration.

Bob Ellis is Chair of SIGGRAPH's Public Policy Committee. When last gainfully employed (1993), he was Sun Microsystem's representative on the Computer Systems Policy Project's (CSPP) Technology Committee and also co-managed Sun's external research program. Before that Ellis held computer graphics software development and management positions with Sun, GE-Calma, Atari, Boeing and Washington University (St. Louis).

Bob Ellis

The copyright of articles and images printed remains with the author unless otherwise indicated.

Digital Watermarking

Digital watermarking is the subject of a highly recommended (by me) special section of the July 1998 issue of the Communications of the ACM (CACM). Quoting from the Guest Editor’s (Minerva M. Yeung) introductory article, we see that “Digital watermarking is the embedding of unobtrusive marks or labels that can be represented in bits in digital content. The embedded marks are generally invisible (or imperceptible) but can be detected or extracted through computing operations and is why they are called digital watermarks. The watermarks are bound to and hidden in the source data, becoming inseparable from the data (such as images and audio and video clips) so they can survive operations that do not degrade the data beyond its utility value in the intended applications.

“Data encryption and scrambling technology offer security for content delivery, as well as the means for controlling access and collecting revenues. But a key (in the cryptographic sense) to decoding or descrambling the encrypted or scrambled data will be available only to the content’s (paying) patrons... Unfortunately, there is little, if any, protection for decrypted or descrambled content...” Thus digital watermarking is complimentary to encryption because it can protect non-encrypted material.

“Watermarks can also be used to communicate copyright, ownership, and usage-control information - even after format conversions and compression. Watermarking technology, if designed properly, can be used for proof of ownership, as a content authentication tool, and as a means of imprinting fingerprints into the data to allow tracing of the recipient should the data be misappropriated.”

Individual papers in the issue cover topics such as: techniques, applications, needs of the content owner, content user and attacker, benchmarking, performance evaluation, standardization opportunities, the business case and market perspectives. While I believe that the technology is not yet fully developed, it shows significant promise, and its progress should be followed by all those concerned about the identification and protection of digital media.

In an ideal juxtaposition of topics, the July 1998 issue of CACM also has a special section on Web information systems. While perhaps not as much of interest to computer graphics professionals as digital watermarking, it does provide a timely overview of the subject in a series of short articles. Again, I highly recommend it.