Fast from 16bit to gtk image buffer

[Piotr Legiecki <piotrlg sci pam szczecin pl>]

Hi

I'm new to gtk.

I'm writting simple program which will operate on 16bit per RGB channel 
(tiff, scanned images) files. After a quick research on this list and 
others currently I know, that gtk (ie gdkpixbuf and the rest) doesn't 
support 16bits image depth.

So I'm on my own to read tiff files somwhere in memory and then convert 
them to some gtk image buffer to display it in a window.

Generally i know what to do, but I'd like to ask you a question about 
the most efficient (fast) wey of pixel buffer structure.

gtk uses something called packed data structure for pixels right? So 
each image line looks like this:
RGBRGBRGB......rowstride

When I read in the 16 bit tiff file (using libtiff) it will be stored in 
a known place but I don't know how. So what is the image buffer 
structure of this read-in tiff file?

I wonder if it is possible to operate on such 16 bit images (huge: about 
 4000x2500 or more) in almost realtime? Just like gimp where I can 
chagne the levels, operate on curves etc and the changes are applied to 
the image at once. My operations will be generally also rather simple 
ones so I hope there will be no need for preview window.

So in summary:
I want to manipulate 16 bit per channel image and display the changes as 
fast as possible using gtk window (not sure if gdkpixbuf or GdkRGB).

Regards
Piotr L.