Digital Image
Watermark Digital Image
Watermark
An Approach to Digital Image Watermark based on the Wavelet Coding
A new method for digital image watermarking which operates in the frequency domain is under development. The method is based on the insertion of a pseudo-random sequence of real number in those image frequencies which are most resistant to common signal distortion. The number of frequencies to be modified and the magnitude of the modification depend on the particular image: they are optimized in order to ensure a good resistance to tampering coupled with a very low perceptibility level.The watermark insertion and extraction procedures can be summarized as follows:
Original Image |
DWT
|
Wavelet Transform |
 Watermark |
|
Embedding procedure |
Watermarked Image |
InverseDWT
|
Marked Signal |
Watermarked Image |
DWT
|
Wavelet Transform |
|
 Original Image |
|
Extraction Procedure |
|
Searched Watermark |
Similarity Function
|
Extracted Watermark |
|
Similarity Value |
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