Watermarking

In the wake of increasing copyright misuses, several new technologies are developed to preserve the authentication of information. Digital water marking is one of them. It is a technique that allows us to add hidden copyright notices, verification messages or any other useful information to the original signal. The hidden message can be a group of bits that describe something about the signal or about the genuine author of the signal.
WATERMARK INSERTION:
Mid frequency components are chosen for embedding the watermark in a simple way, owing to the shortcomings with the low frequency components and high frequency components. The difficulty with the low frequency components is that they are highly susceptible to distortion. The high frequency components do not bear much of information reliably, since their removal from the actual signal does not affect the signal’s quality too much.