Digital watermarking for jpeg/png

Question

I need a program that will embed an invisible mark (not big text info, 256bytes max) in an image. But I could not find a good library (in any language, better if c/c++). I found a lot of literature, but no source code.

I found one resource but that program is writtem for NetPBM format.

The needed method is not LSB, or concating etc.

Magnetoelectricity

Welcome to stackoverflow! I tried to improve the grammar in your post, but I'm unsure what you mean with The needed method is not LSB, or concating etc... You should explain why a least-significant bit encoding is not sufficient for your cause. – Ajax

In perfect this method must be suitable for elementar deformation(like rotation and expansion if that possible), if Im not mistaken LSB is not so stable for deformation. Inreal my boss said, that will be better, if it wil be not LSB – Magnetoelectricity

@Magnetoelectricity You should try to separate your concerns if at all possible. For example. If you want to rotate images, you can do batch rotation with something like Gimp. Try to explain the problem in a little more detail. – Vampirism

User of system will download a jpg file, on his computer, before this, I should to embed a special mark(with user id), on it. After user do with this file all he want(rotation, expansion and so on). But it should be possible, always, if I get this file, to extract mark, and know who download that file – Magnetoelectricity

Answer 1

Have a look at steghide, an open-source steganography program that supports JPEG.

Ajax

thanks a lot for this resource, but it`s needed a programm for digital watermarking? – Magnetoelectricity

Sorry, I don't understand. steghide is a program for steganography, i.e. embedding hidden content in a file without allowing an attacker to detect something is embedded in the file. It is intentionally fragile. If you want the added content to survive transformation, you're not so much looking for robust digital watermarks. If that's the case, please open a new question where do you describe your needs in detail. – Ajax

Is ther a similar solution that can utilize secret image, rather secret text? – Eby

Answer 2

If you just want to track images with a user id, then you should edit the image EXIF data. There are thousands of libraries out there to do just that. Here is one for C http://libexif.sourceforge.net

Vampirism

An invisible watermark is a form of steganograpy. See: en.wikipedia.org/wiki/Steganography. If you just want to put normal watermarks on a whole lot of images, then use Gimp in batch mode. – Vampirism

Yes, but it is specific for images, because if you change somethig in binnary, but image will looks like original, you could take the mark, if it will be usual stegnography, even rotation< and you could not see the mark. Can GIMP make invisible watermarks – Magnetoelectricity

There are a lot of ways to remove EXIF data. It's not used for protective but descriptive purpose. – Eby