png metadata

[Toby Kelsey]

Duncan Lithgow wrote:
> Does anyone know what can write metadata in a png file?
> 
> I'm looking for a good way of embedding information about some
> historical images _into_ the image itself - so they never get seperated
> from each other.
> 
> Suggestions anyone?
> 
> Duncan

I don't think there is a standard convention for adding comments in png, although
http://en.wikipedia.org/wiki/PNG mentions the 'iTXt', 'tEXt' and 'zTXt' chunks.

The 'convert' program can add comments for 'supported formats', whether this includes PNG I don't know.

A google search found these relevant pages:

http://www.digikam.org/?q=node/62
http://heim.ifi.uio.no/~gisle/blog/index.php?p=3

There is one program 'pngmeta', which can handle metadata and might do what you want:

http://www.libpng.org/pub/png/apps/pngmeta.html
http://pmt.sourceforge.net/pngmeta/

Let us know how you get on.

Toby