A robust spread spectrum watermarking method using two levels DCT. (29th July 2009)

• Record Type: Journal Article
• Authors: Taherinia, Amir Hossein; Jamzad, Mansour
• Is Part Of: International journal of electronic security and digital forensics. Volume 2:Number 3(2009)
• Page Start: 280
• Page End: 305
• Publication Date: 2009-07-29
• Subjects: blind digital watermarking -- DCT -- spread spectrum watermarking -- copyright protection -- digital multimedia data -- spread spectrum communications -- electronic security; Computer crimes -- Periodicals; Computer crimes -- Investigation -- Periodicals; Computer security -- Periodicals; Electronic commerce -- Law and legislation -- Periodicals; Information warfare -- Periodicals; 005.805
• Languages: English
• ISSNs: 1751-911X

Abstract

In this paper, a DCT-based blind watermarking scheme based on spread spectrum communications is proposed. We perform block-based DCT on the host image; then using the DC coefficients of each block, we construct a low-resolution approximation image. We apply block-based DCT on this approximation image, then watermark is embedded by adding a pseudo random noise sequence into its high frequencies. In detection stage, we extract the approximation image from the watermarked image, then the same pseudo random noise sequence is generated, and its correlation is computed with high frequencies of the watermarked approximation image. In our method, higher robustness is obtained because of embedding the watermark in low frequencies. In addition, higher imperceptibility is gained by scattering the watermark's bit in different blocks. Compared with related works, our method proved to be highly resistant in cases of many common attacks, while preserving high PSNR for the watermarked images.