The Attacking Method for DC Components Watermarking

In this paper we present two methods to remove the watermark from the carrier image, which is embedded in dc components of the discrete cosine transform based image using the method presented by Huang et al. [1] The first method, which we present, removes the watermark via varying the energies in frequency domain and redeeming the luminance in spatial domain; the second method we present removes the watermark through diversifying the intensity of dc components in transform domain. Both the two methods can remove the watermark and avoid to be detected that the image was hidden a watermark by the detection criterion. In addition, though we cleaned the watermark from the watermarked image, the PSNR of the cleaned image (compared with the original carrier image) is still high.