Research Article
A QR Code Based Zero-Watermarking Scheme for Authentication of Medical Images in Teleradiology Cloud
Algorithm 2
Watermark construction.
: Host image of size , Secret Share of size , Key for initial | block Selection, size of block , Number of iterations for Arnold Transform | : Watermark of size | Step 1. Apply Contourlet Transform on to generate a LF subband | Step 2. Perform a block partitioning on the LF subband to generate overlapping | blocks | Step 3. Perform steps 4–9 for each element of | Step 4. Apply Arnold transform on to select a block for Master Share creation; | Increment and by 1; i.e., and | Step 5. Apply SVD to selected block to generate and matrices | Step 6. Compute the Hu’s invariant moments and for the diagonal matrix | Step 7. Create a 3 bit Master Share out of the sign bits of and | Step 8. Compute C from Sshare with equation (10); | i.e., where | Step 9. Subtract from to get | Step 10. Apply Arnold Transform to unscramble to get |
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