Resumen
The article reports that due to the proliferation of the World-Wide Web, a huge amount of multimedia content text, graphics, images, video, and audio are available for browsing and downloading by millions of users worldwide over the network. As a result, security and copyright issues have become important problems in research and applications. Current copyright laws are perhaps inadequate for dealing with digital data, leading to interest in developing other copyright protection mechanisms, including digital watermarking techniques. Digital watermarking is applicable in copyright protection, ownership assertion, and integrity checks in multimedia content. A visible watermark typically contains a visual message or a company logo indicating ownership of the image. An invisible watermarked image is visually very similar but not necessarily identical to the original unmarked image. The existence of such a watermark can be determined only through a watermark extraction or detection algorithm.