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劉晟志2010/03 /21
Homework 1.watermarking
Hide “nsysu logo” into the 3rd bit plane
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)
5% 10% 15% 20%
Add black spot noise with different occur rate (binary watermarking)
5% 10% 15% 20%
Different JPEG compress rate
5% 10% 15% 20%
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
End