GDK-Pixbuf question, creating and reading private data-chunk for png

[Arne Pagel <arne pagelnet de>]

Hello,

I am using gdk_pixbuf_save to store a gdk_drawable into a PNG File.

Now I want to add a private data-chunk to PNG to store some additional Information.

Is it possible to add a private data-chunk with GDK functions?

If not, what do you think would be the best way to create this file?

Using libpng with png_set_unknown_chunks() ?

Is there any examplke of how I get GDK-IMAGE-DATA to libpng?

regards
  Arne