Visible and Invisible Watermarking Methods for Quality loss of data

Abstract

Watermarking is the technique of adding watermark inside image in such a way that when an unauthorized user tries to use the image with a watermark, he can be caught on the basis of copyrights grounds. Addition of Watermark can be done in visible and invisible manner. Visible watermark places a watermark over an image in such way that it is visible to all the users about the owner of the image and invisible watermarking is done in such a way that watermark content is hidden from the user. This paper presents both invisible and visible watermarking methods applied on digital images for copyright protection and number of attacks that are applied on watermarked images to test the quality of a data. In our purposed scheme we are going to apply DWT (Discrete Wavelet Transform) to both visible and Invisible Methods. The results are calculated by implemented our purposed scheme with the help of Graphical User Interface in MATLAB 7.6.0. The results are formulated by the calculation of PSNR and BER.