Manipulating large graphics

[Scott Gifford <sgifford suspectclass com>]

I'm working on an application that deals with extremely large graphics
--- it loads in images of forms and lets you type on them.  Right now
I'm just using a GdkPixbuf, and have run into some of its limitations.
A scanned 300dpi form that's 8.5x11 inches is 8.4 million pixels, and
with 24bit color, over 25MB of memory!  The viewed image is much
larger than the screen, and flickers when it is manipulated.  And I
have to convert PostScript and PDF files into PNGs to edit them.

I'm trying to find a straightforward way to reduce memory usage, to
allow zooming in and out, and to support PostScript and PDF image
formats.

Anybody got any pointers?  

The code and more information about the project is at:

    http://www.suspectclass.com/~sgifford/proforma/

Thanks,

----ScottG.