[Bf-python] Saving image data

[karamike]

Am 05.08.2014 um 20:27 schrieb Campbell Barton:
> Checked and it works here, probably the image you're saving isnt a
> jpeg, thats because `save_render` uses scene settings, ignoring the
> one in the filename.
>
> See this answer for details on setting the image format.
> http://blender.stackexchange.com/a/6867/55
>
Thank you - but this did not work either.
Neither setting the image format to PNG in the UI nor via Python changed
the result.

However, I found the problem.

As stated above, the output of print(image.source) is VIEWER.
I now found what that means: "Viewer, Compositing node viewer"

The compositor hadn't been set up.
After I clicked "Use Nodes" I can save the image via the scripts.