Is there a way to rotate bpy.data.images -for example 90 degrees clock-wise- or do I need to do it externally?
Or even better - is it possible to rotate the view in the UV Image editor without actually change the image?
You can manipulate the UV data from python, so you could rotate the UV and it’s not very complex because UVs are 2D data, so the rotation is in 2D space.