Research Article Open Access

Combined DWT-DCT Digital Image Watermarking

Ali Al-Haj


The proliferation of digitized media due to the rapid growth of networked multimedia systems, has created an urgent need for copyright enforcement technologies that can protect copyright ownership of multimedia objects. Digital image watermarking is one such technology that has been developed to protect digital images from illegal manipulations. In particular, digital image watermarking algorithms which are based on the discrete wavelet transform have been widely recognized to be more prevalent than others. This is due to the wavelets' excellent spatial localization, frequency spread, and multi-resolution characteristics, which are similar to the theoretical models of the human visual system. In this paper, we describe an imperceptible and a robust combined DWT-DCT digital image watermarking algorithm. The algorithm watermarks a given digital image using a combination of the Discrete Wavelet Transform (DWT) and the Discrete Cosine Transform (DCT). Performance evaluation results show that combining the two transforms improved the performance of the watermarking algorithms that are based solely on the DWT transform.

Journal of Computer Science
Volume 3 No. 9, 2007, 740-746


Submitted On: 14 October 2007 Published On: 30 September 2007

How to Cite: Al-Haj, A. (2007). Combined DWT-DCT Digital Image Watermarking. Journal of Computer Science, 3(9), 740-746.

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  • Digital image watermarking
  • image copyright protection
  • frequency-domain watermarking
  • Discrete Wavelet Transform (DWT)
  • Discrete Cosine Transform (DCT)