I have an idea of applying DCT on an image and then embed text into the LSB of the coefficient of DCT and transmit the image to B (the receiver). Now, using the same procedure, can B transmit another watermark along with the previous one with this method to another person? Is this a suitable procedure?
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I'd say no, unless A and B had some rules so they wouldn't write over each others information. maybe they would agree that odd bits would be used by A and even bits by B. But this halves your secret bit rate, and the bit rate of a hidden message using the LSB of a DCT is pretty small already I'm guessing.– danielApr 11, 2017 at 11:24
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@daniel There are algorithms that can provide error correction and detection with arbitrary precision (e.g. reed-solomon codes), which could provide resilience against a given number of bits being corrupted by another party.– forestFeb 21, 2018 at 6:34
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@Sana Is this suitable for what? Yes, it would work in that you could embed information in a (lossless) image, but what is the purpose? No one can answer you as to whether or not it is a suitable procedure if no one knows what it is necessary for.– forestFeb 21, 2018 at 6:36
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@forest what do you mean? What happens if you have 1 message of 100 bits, and a nose source of any given number (up to 100 bits) en.m.wikipedia.org/wiki/Channel_capacity– danielFeb 21, 2018 at 7:01
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@daniel Obviously error correction codes expand the amount of data required to hold a given message. The method of transmission is irrelevant. All that matters is that an (ECC-protected) message of a given length is able to withstand the corruption of an arbitrary number of bits (no bits are more important than any others).– forestFeb 21, 2018 at 7:26
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Since you usually compress images, which would do something very similar, at least in the case of jpeg compression, but would completely omit or severely reduce LSBs, I guess, no, in practice not.
If you're sending around full-color pictures uncompressed, at least I'd look at the entropy of your LSBs and the PSD, and the latter would probably lead to the suspicion that you're using steganography.
answered Apr 11, 2017 at 6:44
