I will file a message digest is, after the signature is embedded into the image, then image as a watermark is embedded into the file,

Verify the signature, extract the signature information in the image, decrypted message digest, but after these operations, file message digest changed,

I see a lot of papers are separated, why other people's files will not change a message digest??????

Beg god explain this!!!!!!!!!!!!!!!
The younger brother grateful, my graduation thesis in the last step is verified, only to find the problem,,,,,,,
Please deliver!!!!!!!!!!