A Review on Digital Image Watermarking Using Transformation and Optimization Techniques

Now-a-days multimedia data is being generated very frequently in text format, image format, audio format etc. Security is the major issue of the multimedia data. Multimedia data can be very easily modified by the intruders. By using Watermarking and Steganography techniques the multimedia data can be protected from unauthorised access. Watermarking technique hides the data in the carrier signal. In the process of Steganography, the digital data (e.g. digital files like audio, video, text etc) can be embedded into some other digital file. The concept of watermarking is to keep the watermark robust from various attacks. Whenever the intruder tries to temper with the digital signal and removes the watermark, the digital data becomes useless as the quality is degraded. This paper discusses about various applications of watermarking, characteristics of Watermarking and basics of image processing. This paper also provides a comprehensive study of available literature on digital image watermarking. Some of the optimization techniques have also been discussed.