Handwritten notes can be manually pulled from the database\media\notepads directory of the Reader's main memory. For those that are so inclined, multiple notes can be parsed, plotted, and combined into a single pdf in a few lines of code, e.g., in python or something else. (This is what I've been doing for notes taken at meetings.)
If you want to convert to a raster format, the .note files appear to be in an odd SVG format that doesn't render properly in some viewers.
The GIMP, in linux at least, can import and convert them without a problem; you'll just need to manually specify a width/height.