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Homework 1. watermarking. 劉晟志 2010/03/21. Hide “ nsysu logo” into the 3 rd bit plane . PSNR : 42.092 dB. O riginal. Post. Discuss: why can’t we extract the watermarking after doing the “Noise adding” by Photoshop? Every pixel had been change during the process
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Homework 1.watermarking 劉晟志 2010/03/21
PSNR: 42.092 dB Original Post
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
Add black spot noise with different occur rate (gray level watermarking) 10% 20% 5% 15%
Add black spot noise with different occur rate (binary watermarking) 10% 20% 5% 15%
Different JPEG compress rate 10% 20% 5% 15% Cover image Water marking
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