08-07-2014, 11:39 AM
A Robust Digital Image-in-Image Watermarking AlgorithmUsing the Fast Hadamard Transform
A Robust Digital.pptx (Size: 778.24 KB / Downloads: 11)
Objective:
A robust image-in-image watermarking algorithm based on the fast Hadamard transform (FHT) is proposed for the copyright protection of digital images and it use “blind” watermarking process.
To increase the invisibility, a visual model based on original image characteristics is proposed and to increase the reliability of the watermarking, a post-processing technique is proposed.
Existing method
Most research makes use of a normally distributed random vector as a watermark and where the watermark can only be detected by cross-correlating the received coefficients with the watermark generated by secret key and then comparing an experimental threshold value.
Techniques in watermarking:
One is the spatial domain approach, they embed a watermark into the least significant bits (LSBs) of the image pixels.
The other is the frequency domain approach, used the spread spectrum communication for digital multimedia watermarking and they embed a Gaussian distributed sequence into the perceptually most significant frequency components of container image.
CONCLUSION
A hybrid watermarking technique for embedding characters or grayscale image watermark into a container digital image based on the FHT for copyright protection is presented.
Proposed method is robust against most of the Stirmark attacks and Checkmark non-geometric attacks.
This offers a significant advantage in shorter processing time and ease of hardware implementation