Digital Watermarking

Digital Watermarking is a particular technique that permits a person to add hidden copyright messages or other verification notices to digital audio, video and image documents. Those message is a group of bits that deals with information referring to the author of the signal. This specific term name has been taken from watermarking of paper or money which is meant for security purpose. Digital watermarking can be a stenography form, in which data is incorporated in the message in the absence of users' knowledge.

A remarkable example of a digital watermarking could be a visible "seal" placed over an image for the purpose of identifying the copyright. Aside this the digital watermarks can be divided into two types. Such as visible and invisible. Visible watermark is a semi transparent overlaid that wrap up the primary image.

Visible watermarks is able to bring such a rapid change that the watermarked signal is totally different from the actual signal. Generally Stock photography agencies are seen to add a watermark in the shape of a copyright symbol in order to prevent the use of previews for high-quality product copies.

The two major functions of the Visible Digital Watermarking are as follows

copyright protection

ownership originals