A digital watermark is a used for identification of embedded data in a noise tolerant signal such as image data. It is used to identify ownership of the data. "Watermarking" is the process of hiding digital information in a carrier signal. Embedding a digital signal is called as watermarking. Robust Watermark is well suited for copyright protection because they stay intact with image under various manipulations. Security issues regarding images are important because images are used in electronic media. In this paper we discuss the issues like robustness, security, compression, capacity and fault-tolerance of these watermarking methods.

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Image Watermarking Robust Watermark Fault Tolerance Security