A Semi Blind Watermarking Technique for Copyright Protection of Image Based on DCT and SVD Domain

Abstract

With the rapid use of digital data in information technology and multimedia, piracy and malicious manipulations have become a common concern, thus it is inevitable that the digital content is protected. Hence copyright protection has become a vital issue. Digital watermarking has emerged as a solution to this problem. In this paper, a watermarking technique is proposed and implemented. In which the original image is sorted out to another form by applying zigzag process followed by DCT and SVD. Watermark is then embedded by modifying the singular values and extraction of watermark is the inverse process of embedding. The deliberated algorithm gives good Peak Signal to Noise Ratio (PSNR) which ensures good imperceptibility and Normalized Cross Correlation (NCC) which ensures more robustness against different kinds of noise such as Histogram equalization, JPEG compression, Speckle noise, Gaussian noise, Salt and Pepper noise, Cropping, Rotation, Sharpening and so on.