What is Digital Watermarking?

What is Digital Watermarking?

by Stephanie Morrow, December 2009

With millions of Web sites flooding the Internet, it may seem easy for on-line pirates to copy and paste information, images, video and audio from one Web site to another, blatantly infringing on someone else's copyright. However, owners of copyrighted materials on the Web can take advantage of "digital watermarking" in order to protect their materials from being duplicated without their permission.

Traditional watermarks have been used for years on letterhead or checks to prove authenticity. A watermark is a name or logo stamped on or included in the makeup of the paper. Some watermarks only appear when you try to copy a document; copies of checks frequently have "void" on the front of them. Traditional watermarks are also used on currency to prove that the money is not counterfeit, such as the new $100 bill's watermark of Ben Franklin.

Digital watermarks are the electronic versions of their traditional counterpart. Originally used in the photography market as a way of identifying the copyright owner of digital photos, digital watermarking is a means of embedding data into digital and analog content in order to identify its owner. The watermark becomes a permanent part of the content, even as it is distributed to others.

Like traditional watermarks, digital watermarks in video, audio and images inform the viewer or listener of their rightful owner. Digital watermarks can also be used by the original owner to monitor and track how the materials are used. Finally, digital watermarks are also useful to viewers because they can provide links to the original owner and to related information.

Added Protection

Digital watermarks cannot be removed or altered, making them a very important tool when fighting copyright infringement on the Web. Digital watermarks allow users to legally use content, while adding security to the content to prevent illegal usage. Digital watermarks are "robust," meaning they are able to survive attacks from potential hackers or any type of manipulation, in addition to providing information about the original owner.

Visible or Invisible?

Invisible digital watermarks are generally undetectable to the human eye and ear, but can be detected by computers, DVD recorders, digital cameras or other devices that are equipped with the appropriate software. If an image is used illegally, an invisible watermark not only notifies the user of the legal copyright owner, but may also show the prosecution methods the owner will use if the image is used or copied illegally. To combat the estimated 500,000 movies illegally downloaded every day, the movie industry frequently uses invisible watermarks causing the words "do not copy" to appear on illegal copies.

Visible watermarks are similar to watermarks used on paper, such as a copyright notice, a verification message stating who owns the material, or the addition of a digital stamp. Since visual watermarks change the look of an image or video, they are effective in eliminating potential commercial value for Internet pirates. You can't claim to own an image with someone else's logo on top, or a video with another television station's logo in the corner.

The Future of Digital Watermarking

A number of companies, such as the Digimarc Corporation, Sony and IBM have introduced digital watermarking software applications that allow individuals to imbed watermarks within image, audio and video files to protect them from copyright infringement. The watermarks may be viewed with software and can reveal either a unique identification code that can be traced to the copyright owner or specific information about the copyright owner.

Companies are also offering on-line tracking services so that the copyright owner can see how the owner's materials are used via the Web. These processes will continue to help the fight against electronic copyright infringement.

If you feel you are a victim of copyright infringement, discuss your options with an intellectual property attorney.