Comment 2 for bug 583124

Sorry I had not looked into the tests yet. I fixed take_screenshot to grab only a part of the screen and now all tests succeed.
The temporary file was a quick hack because I could not find documentation how the numpy array of gtk.gdk.Pixbuf.get_pixels_array can be build.
But I have to agree it would be even better to not depend on any heavy toolkit. My branch currently only needs PyQt for taking the screenshot.
I found some code to do it with xlib but again I don't know how to create the numpy array. Do you have any idea?