If I embed some information in an image using steganography and then I print that image, will I be able to retrieve information from the printed image or not?
$\begingroup$ No luck with my forensics paper in crypto.stackexchange.com/a/70233/23115 ? $\endgroup$– Paul UszakMay 8, 2019 at 12:51
$\begingroup$ Don't you remember from the history the hair of the messenger is cut, the message is written the to the bald head, then waited for the hair grow, and after that, the messenger allowed to travel and in the destination again cut to release the message. $\endgroup$– kelalakaMay 8, 2019 at 15:20
It depends on the steganography method you're using, and on how the image is printed.
Most steganography methods designed for digital images probably won't survive printing and scanning the image, or at least doing so will introduce a significant amount of noise into the concealed data that will exercise the error correction pretty hard and significantly limit the maximum payload capacity.
However, there are also steganography and watermarking methods that are designed to survive printing, or even designed specifically for printed images. Indeed, you may have already unknowingly included such watermarks in your prints, if you've printed them on a printer that embeds a machine identification code in its output.
Most certainly no. If you are using a "classic" LSB based algorithm with uncompressed images you would have to be able to scan the printed image and end up with the exact same pixel values, which I don't think is possible. I mean the scan would have to result in the same file. At least if you are using a "good" algorithm which does not alter the cover image in any noticeable manner.