run control.py to start the program
The watermark pictrue is fingerprint.jpg.It will be processed by Median filter, gray scale, black and white binarization.Then we get the picture named embedfinger.jpg
The host picture is host.jpg.It will be processed by RGB-to-YUV,uint8-to-float32.Because we will DCT on the Y dimension which means the value of brightness later,and DCT need float32.
- Divide host into 8x8 blocks.
- Calculate
the average numberof fingerprint pixels to be stored for each 8x8 block.You can see outputris it. - Each block on the Y dimension DCT for the airspace change into frequency domain.Then we discuss the operation to 8x8 blocks in frequency + domain.
- In a 8x8 block, the unit cell,and its symmetric unit cell of the center,become a pair,named r1,r2
- Each pair of relationships (r1>r2,r1<r2) is used to record the 0-black and 255-white of the fingerprint pixels to be stored.
- Embed the average number of fingerprint pixels into mid-frequency cell of the 8x8 block.
- Each 8x8 block on the Y dimension inverse DCT for frequency domain change into the airspace.The finished product is
finishwm0.jpg(finish0~5.jpg are different intensity of JPEG compression,finishwm0.jpg is best quality,finishwm5.jpg is worst quality.)
Just 8x8 DCT and find embeded location,then sure the average number of pairs' relationship(r1>r2 is 0-black and r1<r2 is 255-white).Constitute Y dimension of original watermark named 0extractfinger.jpg(0~5)
Calculate PSNR and observe products from different JPEG compresstion.