A digital watermark is a small, almost unnoticeable alteration to a digital file like an image, a photograph, video or a sequence of sounds. The information is encoded through subtle changes to the image, video or sound. These changes typically would not be perceptible to a person, since the digital watermark is designed to be detected and decoded only by specific software.
Digital watermarks can be used to embed identifying information into the digital work. Moreover, software that works with images can automatically detect the hidden markings and act accordingly — not permit copying, for example. If the watermark contains a serial number, any given copy of a watermarked work can be logged and recorded somewhere, allowing the author to track down the source of unauthorized copies.
Digital watermarking can operate with both networked and non-networked technologies. Because digital watermarks remain embedded in the content through subsequent manipulations, copying, and format conversions, they permit this technology to be used across a variety of media delivery platforms including television, cable, satellite, wireless devices, non-networked devices, and the Internet.
The number of bits that can be contained in a digital watermark today is modest — enough to provide some basic codes or identifiers, but not enough to include the equivalent of a full sentence of text.
Privacy concerns Edit
|“||Perhaps the most frequently raised privacy concern is the idea that watermarks could enable increased monitoring, recording, or disclosure of an individual’s media purchases or usage. The fear, in other words, is that watermarking could compromise an individual’s ability to use and enjoy lawfully acquired media on a private, anonymous basis. Particular media usage choices could be sensitive if exposed, or could contribute to the creation of profiles of individuals’ overall media purchase and consumption habits, which might be used in ways that the individuals do not expect or understand. Other possible privacy concerns include the risk that watermarks could contain personal information that could be exposed to third parties, and the risk that errors in or manipulation of watermark data could paint a false picture of an individual’s behavior and perhaps lead to adverse consequences, including potential legal liability.||”|