[cairo] Copying PDF to Image (Blurry result)

[Ian Britten]

Hi all,
     [ cairo 1.8.6, pixman 0.14, 64-bit Linux ]
I have a PDF surface containing vector data, and I want to copy a
small portion of it to a large(r) image, basically producing a
high-resolution image of a part of the source area.

My first attempt, based on
     http://cairographics.org/FAQ/#paint_from_a_surface
has produced less than desirable results, as can be seen at
     http://img52.imageshack.us/img52/2808/output.png
My test program can be seen at http://pastebin.ca/1940844

As you can see, the resulting image is blurry/etc.  To me, it seems
that the copy operation might have rendered into a small image, and
then stretched the image, producing the blurriness (from resampling?).

I would have thought that since the source was vector, the
copy operation would have 'replayed' the vector instructions onto,
the image, effectively redrawing the vector data onto the image
(ie: high quality).

Is my expectation wrong?  Should I be able to get what I'm
expecting, namely a high-quality enlarged image?  Or am I
off-base?  Or maybe doing it the wrong way?
Many thanks for any info, pointers, etc!
Ian