Watermarking based on 2D-FFT with Encryption using Arnold’s Transform for Color Images
P R Shalini, Gururaj Bijur · 2011
In this paper, we present a method for copyright protection of color images in Fourier domain by using spread spectrum watermark embedding. The cover image here is a color image in the RGB color space, into which the binary watermark image is embedded. The watermark image to be embedded is scrambled using Arnold’s cat transform and the encrypted watermark is embedded, which gives a level of security to the watermark .The cover image in the RGB color space is first converted into YCbCr color space, in which it is represented by luminance (Y)and chrominance (Cb and Cr) color values .Then block based two dimensional Fast Fourier transformation is done on the luminance channel and the watermark is embedded by modifying the magnitude co-efficient in the high frequency band. Correlation method is used in extraction of the embedded watermark. The proposed watermarking algorithm proves to have better time complexity, imperceptibility and robustness.