On Sat, 2004-09-18 at 20:22, James Britt wrote:
> 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.

Great! this does look do-able, I was hoping there might be something
like this to do but was a bit clueless and some documents discussing
hardcore steganography are a bit scary.
thanks,

Daniel