Spread Spectrum Watermarking: Zero Rate Embedding to High Payload System

This article presents a brief review on non-blind and blind spread spectrum (SS) watermarking developed for multimedia signals. The discussion gradually moves from zero-rate embedding to high payload and variable embedding systems that take into consideration the issues of host signal interference rejection, payload problem and decoder structure robust to non-stationary fading like attack. The algorithms have been discussed from mathematical perspective to theoretical derivations with the aid of soft computing techniques to optimize the system performance. The outcome of the review articles generates few open research problems on SS watermarking.