Mahsa Shakeri - Department of Computer EngineeringSharif University of TechnologyTehran, Iran
Mansour Jamzad - Department of Computer EngineeringSharif University of TechnologyTehran, Iran

Watermarking is a way that is used to protect thecopyright of images. As the existing watermarking methods are notrobust enough a new novel scheme is needed. In this paper, wepropose a zero-watermark discrete cosine transformation-basedcopyright protection scheme, in which a normalization procedure isapplied in both watermark embedding and extraction to make ourscheme more robust to geometric distortions. This method isresistant to malicious signal processing and geometric attacks suchas blurring, JPEG compression, noise adding, sharpening, scaling,rotation and cropping. Experimental results on images withdifferent complexity show that our proposed scheme outperformsrelated methods in most cases. Moreover, our proposed method islossless, i.e., with no modification on original image, and does notrequire original image for watermark extraction

Copyright protection, zero-watermarking,discrete cosine transform, image normalization, robustness,lossless