Robust Digital Watermark on DCT Transform Domain

After taking binary image as watermark,this paper proposes a robust digital watermark arithmetic based on Discrete Cosine Transform(DCT) transformation domain.The watermark image is scrambled,and scramble number is used as the key when extracting watermark,then the watermark image and initial image respectively in block DCT transform are transformed.Each block of the watermark image is embedded into a plurality of the blocks of the initial image in order to make the embedded watermark have strong robustness.Experimental results prove that the arithmetic is of better robustness,invisibility,and resistance the attack to loss compression,cropping,randomly altered,white noise and so on.