With the gradual maturation of multimedia technology and the rapid development of network technology, it becomes more convenient to access and disseminate digital information, such as digital images, audio and digital video. Currently, the rapid escalation of the Internet has made the issue of protecting copyrights of digital contents very much important. Therefore digital watermarking technology is the most commonly researched and applied method to protect intellectual property rights. The paper acquaints the comparative study of Spatial and Frequency domain watermarking scheme for copyright protection of digital images with the purpose of defending against digital piracy. A novel scheme to embed and extract binary image watermarking in gray image based on LSB and DCT domain with their comparative results are also presented. The paper recommends frequency based techniques for achieving imperceptibility and robustness in digital image watermarking. By the use of Matlab software, the efficiency of the proposed watermarking scheme has been demonstrated via the experimental results.

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Spatial domain frequency domain LSB DCT PSNR normalized Correlation (NC) attacks