Daniel Cremer wrote:

> Thank you. Yes my problem is that I would like to use it on JPEGs. The
> most important for me is not to have things encrypted or resist editing
> but to just have an ID and a tiny amount of meta-data encoded into the
> actual jpeg so that it can identified even if the filename changes.

Is this helpful?
http://www.funducode.com/freec/Fileformats/format3/format3b.htm

I only looked at it fairly quick, but it appears to be possible to read 
in a file, insert an 8BIM header with some metadata, update the the SOI 
info (or something along those lines), and write the file back out.

The tedious part is grabbing the correct segments.

http://www.codeproject.com/bitmap/iptc.asp describes doing this.
The sample code is a win32 CPP project,  but the file IPTC.cpp seems to 
have the the important stuff.  Porting to Ruby might be fairly simple.

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the site	.


James