I'm working on digital Image watermarking algorithm through SVD decomposition with DWT2 transform.
After some manipulation with the S matrix (now say s') when i recombine to get the image back(embedding) - on applying SVD again (during extraction) to the recombined image i don't get the same S matrix as s' .
Moreover the final image becomes little truncated itself - i.e. the initial image of 512*512 becomes 504*504.
Please help me guys with this.
Netaji Subhas Institute of Technology