Saving images within Ren´Py?

[gamedriver]

Is there an easy way to save an image file as jpg or as png within a running Ren´Py game? Let´s say I have a big image file which was cropped to a much smaller size by the im.Crop manipulator. Can I get this part of the original image to HDD as a separate file, i.e. not within a savegame?

Thanks in advance

[Imperf3kt]

There's always the screenshot button (s), which can be modified to capture only a specific area, and there are threads on doing that, but I can't find any at this time.