1. Digital watermark in digital images and e-books

2. Why digital watermarking? What is digital watermark? Perceptible and unperceptible watermarks

4. Embedding and detection Watermark properties: - Detectability - Fidelity Optimal embedding strength

5. 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

6. Watermark for e-books Our Virtual library Electronic 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.

7. Unwatermarked PDF page Watermarked PDF page (‘Faculty of Mathematics Belgrade’)