Authors: Arup Kumar Pal; Soumitra Roy
Addresses: Department of Computer Science and Engineering, Indian School of Mines, Dhanbad, Jharkhand-826004, India ' Department of Computer Science and Engineering, Dr. B.C. Roy Engineering College, Durgapur, West Bengal-713206, India
Abstract: In this paper, the authors have presented a robust and blind watermarking scheme based on discrete cosine transform (DCT) for protecting the copyright ownership of digital images. Initially, the image is decomposed into non-overlapping blocks and subsequently DCT is employed on each block to embed a binary bit of watermark into each transformed block by modifying some middle significant AC coefficients using repetition code. During the embedding phase of the proposed method, DC and some higher AC coefficients are kept intact after zigzag scanning of each DCT block to ensure the high visual quality of watermarked image. This scheme is suitable to protect the copyright information even in compressed form of the watermarked image since it exploits middle bands of DCT coefficients for embedding the watermark bits. The proposed scheme is also tested to verify the withstand capability against several image processing attacks and satisfactory results are achieved.
Keywords: blind watermarking; discrete cosine transform; DCT; digital image watermarking; robust watermarking; repetition code.
International Journal of Information and Computer Security, 2018 Vol.10 No.4, pp.321 - 340
Available online: 25 Sep 2018 *Full-text access for editors Access for subscribers Purchase this article Comment on this article