digital watermark


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digital watermark

[‚dij·əd·əl ′wȯd·ər‚märk]
(computer science)
Invisible or inaudible data (a random pattern of bits or noise) permanently embedded in a graphic, video, or audio file for protecting copyright or authenticating data.

digital watermark

A pattern of bits embedded into a file that is used to identify the source of illegal copies. For example, if a digital watermark is placed into a master copy of an audio CD or DVD movie, then all copies of that disc are uniquely identified. If a licensee were to manufacture and distribute them in areas outside of their authorized territories, the watermark provides a trace.

The watermark developer has to find creative ways of altering the file without disturbing it for the user. It is difficult to embed a watermark within an ASCII file, which is just raw text. However, it is relatively easy to alter a few bits within audio, video and image formats without making a noticeable difference on playback or display.


WinZip's Watermark Function
The popular WinZip utility performs numerous functions beyond simply encrypting a file. This is the dialog showing options for adding a digital watermark to certain image files. See WinZip.
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References in periodicals archive ?
The PHISHCUT system utilizes three components: the digital watermarks embedded in websites, specialized software essential for browser terminals, and the Authentication System.
A novel invisible robust watermarking scheme for embedding and extracting a digital watermark in an image is presented [91].
--using the developed software, the manufacturer generates a QR-code with digital watermark and places it on the product label (none additional preconditions for the product labels printing process arise);
Since then Marie Claire, and popular weekly magazines Who and Famous, have integrated digital watermarks into their editorial and advertising content.
This paper is organized as follows: Section 2 explains the advantage of frequency based watermarking, In section 3 proposed algorithm is explained (generation of JND mask and digital watermark embedding and extraction scheme), in section 4 some experiment results are mentioned, in section 5 conclusions are presented.
At the Authentication & Counterfeiting Protection conference in Prague in March, American Bank Note Holographics (ABNH) launched holograms incorporating a digital watermark, following an agreement with Digimarc Corporation.
If digital watermarks are widely viewed by content owners as the way to protect against widespread theft of online images without regard to possible limitations, they may believe that a digital watermark is indelible and empowers them with the tools to deter and police the Web for unauthorized use of their property.
The digital watermark may be inserted either in the raw representation of the image, where each watermark bit is inserted straight into pixel's brightness, or after a preprocessing phase involving the generation of a new domain or/and the selection of an appropriate component on which the embedding algorithm will be applied.
For a digital watermark (32 x 32 block size) embedded in an original image (256 x 256), calculation by the FDCT algorithm in frequency domain and then inverse transform of the encrypted data back to spatial domain image uses 5,653,914 clocks (n = 3), corresponding to 34 ms in 35 KB code size.
Digital watermark is divided into two categories: spatial domain watermark technique and transformation domain watermark technique.
In a public challenge, the SDMI had been offering a $10,000 prize to anyone who could remove a digital watermark from a music file in less than a month.
The embedded information (the digital watermark) can be used later to trace data to its creator, to prove authorship of rights to the material, or to use as a proof of purchase.