digital watermark in digital images and e-books. why digital watermarking? what is digital...
Post on 23-Dec-2015
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Digital watermark in digital images
and e-books
Why digital watermarking?
What is digital watermark?
Perceptible and unperceptible watermarks
Embedding and detection
Watermark properties:- Detectability- Fidelity
Optimal embedding strength
Digital watermark for grayscale images
spread spectrum technique AWGN (additive white Gaussian noise) watermark. Optimal embedding strength - normal distribution properties.
Optimal embedding strength for lossy compressed image
Digital watermark and color image
Each color image is three grayscale images combination
Watermark for e-books
Our Virtual libraryElectronic book (e-book) e-book format (PDF, DjVu)PDF books - classes:• E-books produced by scanning; • E-books originated from DOC or TeX files; PDF file pages
need at first to be converted to bitmaps; watermarking is possible, but not robust enough.
Unwatermarked PDF page Watermarked PDF page (‘Faculty of Mathematics Belgrade’)
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