A new data hiding method using angle quantization index modulation in gradient domain

A robust data hiding scheme that embeds the watermark bits by quantizing the gradient directions of an image is proposed. By embedding the watermark in the angle, the watermark becomes robust to amplitude scaling attacks. To keep the watermark imperceptible and enhance its robustness, it is embedded in the signi cant gradient vectors of the image. The signi cant gradient vectors are obtained using discrete wavelet transform (DWT). Thus, the gradient vector at a pixel is rst obtained in terms of the DWT coef cients. Then the gradient direction is quantized by modifying the DWT coef cients corresponding to the gradient vectors. Experimental results con rm that the proposed gradient direction watermarking (GDWM) method is robust to various types of attacks, specially amplitude scaling attacks, and results in watermarked images of high delity.

• Type: Journal
• Year: 2011
• Where: ICASSP
• Authors: Ehsan Nezhadarya, Z. Jane Wang, Rabab K. Ward
• Keywords: Gradient, Gradient Direction, ICASSP 2011, Signal Processing, Watermark