[cairo] Using cairo to draw into a image and save it

[jody]

Hi
I would like to be able to save cairo drawings on an image to a PNG file.

What i have written so far is code loading and displaying an image,
which can be painted on using cairomm (i simply use the window
on which the  image is displayed as cairo context).
I also have code using the PNG library to create PNG images
from an array of values.

Is there a possibility to either get cairo to do paintings into
some sort of array (which i could write to a PNG file)?

Or is there some other eay to achieve this?

Thank You
  Jody