02-09-2013, 04:56 PM
SELECTION OF FEATURE REGION SET USING HARRIS- LAPLACIAN DETECTION FOR WATERMARKING
SELECTION OF FEATURE REGION.pptx (Size: 144.52 KB / Downloads: 16)
OBJECTIVE
To find the most robust regions from simulated attacking, such as geometric attacks and signal processing attacks
To improve the robustness of the watermarked image and preserve the image quality
MODULES
Feature regions selection
Watermarking
Simulated attacking and Primary feature set selection
Final feature set selection
Reconstruct Watermarking
Watermarking
Input:
Host Image: It is a gray-scale image to be watermarked
Watermark Image: It is a binary image act as watermark
Key: Numeric key used for watermark embedding
Algorithm:
Perform DWT decomposition of the Host Image at level one. Four bands LL, HL, LH and HH are the host images of various resolutions. And store Approximation, horizontal, vertical and diagonal coefficients in LL1, LH1, HL1 and HH1 respectively.
Find the size ofHL1 matrix and store it in S
Initialize the state of Random number generator to Key
For each bit of watermark perform the following steps:
Create a random matrix of size S with random number generator and store it in RHL and RLH
Calculate : RHL1 = round (2*(RHL-0.5))
Calculate RLH1 = round (2*(RLH-0.5))
If bit at current position in watermark has value Zero, then
Set HL1=HL1+k*RHL1
Set LH1 = LH1 + k * RLH1
Perform Inverse Discrete Wavelet Transform (IDWT), to create the watermarked image
Output: Watermarked image: It is a gray-scale image watermarked.