1. 劉晟志 2010/03/21 Homework 1. watermarking

2. Hide “nsysu logo” into the 3 rd bit plane

3. PSNR: 42.092 dB OriginalPost

4. Discuss:  why can’t we extract the watermarking after doing the “Noise adding” by Photoshop?  Every pixel had been change during the process  The noise rate only decides the weight of the noise that will be add to every pixel  As the result, the watermarking can not avoid attack  Add black spot noise

5. Add black spot noise with different occur rate (gray level watermarking) 5% 10% 15% 20%

6. Add black spot noise with different occur rate (binary watermarking) 5% 10% 15% 20%

7. Different JPEG compress rate 5% 10% 15% 20% Cover image Water marking

8. Discuss:  why can’t we extract the watermarking after doing the “Noise adding” by Photoshop?  Every pixel had been change during the process  The noise rate only decides the weight of the noise that will be add to every pixel  As the result, the watermarking can not avoid this kind of noise attack

9. End