Author : Abd Hamza AL-Mayahee, a
journal of kerbala university,
2012, Volume 8, Issue 0, Pages 178-190
This research proposes a watermarking scheme for digital images. It uses a discrete wavelet transform (DWT) prior to the Discrete Cosine transform (DCT) to provide better imperceptibility in harmony with the human visual system, and higher robustness against signal processing attacks.
In this research, DWT is implemented for the cover image, and then applying the DCT to the DWT sub bands, binary watermark (payload) is modulated by exclusive-or (XOR) operation with a key to increase the security of the system and then embedding in the middle frequency DCT coefficients. The key is secret and stored inside the cover image to increase the robust of the system.