# Watermark

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## Watermark

An image in a piece of paper that may be seen more clearly when it is held up to light. This is used in printing some money and passports to prevent counterfeiting. For example, if one holds a \$20 American bill up to light, one would see a watermark of Andrew Jackson's face.
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Prior to joining Watermark, he worked for 12 years at the Federal Reserve Bank in St.
David joined Watermark in 2007 and most recently served as the company's Chief Financial Officer, with responsibility for financial reporting, Human Resources and Information Technology.
When the entropy of the host image is high, considerable watermark information can be embedded into the original image.
Step 2: DT-CWT is adopted to decompose each selected image block, and a watermark bit of "0" or "1" is embedded into each block by scaling the real parts of the DT-CWT coefficients through the following approach:
where "C" is regarded as the correlation between the embedded watermark and the most prominent coefficient of the attacked watermarked and "CK" is the correlation between Kth random
In other words, the watermark image should be hidden to the most prominent selected coefficient of the cover image, so that less effect can be imposed by attacks.
If W is the same watermark that means no pixel in the message M(Y) is tampered and vice versa.
The chaotic maps used are the logistic map given in (1) with initial conditions x(0) = 0.25, r = 3.58 and x(0) = 0.56, r = 3.57 respectively at embedding side and chaotic watermark pattern of size 55x55 is considered for experiment.
(7) Read the second watermark logo which should be made robust and convert it into binary [k.sub.1] x [k.sub.2] matrix.
The other is watermark generation and characteristic digest value generation with direct block division and compressive sensing.
Authors in [37] proposed a watermarking algorithm based on RDWT for biometric watermarks. In this algorithm, speech watermark information is divided into two portions and then inserted into wavelet coefficients of red channel and blue channel of the color face image.
To overcome this challenge of loss of information along with other requirements mentioned-above, not only left but right singular vectors are employed in a unique and novel way (mentioned in section III), to ensure that no significant information is lost and the correct watermark is extracted.

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