Abstract
The multimedia revolution has made a strong impact on our society. The explosive growth of Internet access to this digital information has generated new opportunities and challenges. The ease of editing and duplicating information in the digital domain has created copyright protection concerns for content providers. Various schemes to embed secondary data in digital media have been investigated to preserve copyright and to discourage unauthorized duplication. In order to achieve the required level of protection to digital information, digital watermarking is a viable solution. This paper proposes a novel invisible watermarking scheme: a Discrete Cosine Transform (DCT) domain based watermark embedding and blind extraction algorithm for copyright protection of color images. The proposed algorithm is optimized in terms of robustness, computational load, and quality of the image. Testing of the proposed watermarking scheme's robustness and security via different benchmarks as well as comparison with a DiscreteWavelet Transform (DWT) approach proves its resilience to digital attacks. The results show that the Peak Signal to Noise Ratio (PSNR) value obtained under no attack conditions in the proposed algorithm is above 41.81 dB, which is higher than most of the existing watermark algorithms. The results from the detector's response also show that the proposed algorithm has a better security performance than most of the existing algorithms. The architecture for hardware implementation of the proposed algorithm is also presented and the results from the architecture show a PSNR value of 44.37 dB. This verifies that the presented algorithm is more effective than existing algorithms such as image adaptive watermarking, image adaptive watermark creation, zerotree wavelet, and 9/7 biorthogonal wavelet lifting.