Handling new image format

[foret <foret rsbs anu edu au>]

Hello,

I am writing a scientific software to analyse high resolution scanner 
images using glib and gtk 2.
Unfortunatelly the images are in a 16-bits gray level format which is 
not supported by libtiff (8-bit maximum for gray level images).
What is the best way to had support for this format (and in general to a 
new image format) to gtk/gdk/gdk-pixbuff ?

Thanks !

Sylvain