digital watermarking is a process by which a user-specified

signal is hidden or embedded into another signal , for

example digital content such as electronic documents, images,

sounds and video [2]. The use of digital video applications

such as video-conferencing, digital television, digital cinema,

distance learning, videophone, and video-on-demand has

grown very rapidly over the last few years. Today it is much

easier for the digital data owners to transfer multimedia data

over the internet, and hence the data could be perfectly

duplicated and rapidly redistributed on a large scale. Thus, the

importance of copyright protection for multimedia data has

become more critical. Digital watermarking is an effective way

to protect the copyright of multimedia data even after its

transmission there is urgent demand for techniques to protect

the original digital data and to prevent unauthorized

duplication or tampering.