Hi Florian,
I have tried it, it works pretty well if the data is consistent (all text same size, same font) but poorly in other circumstances. For instance, sometimes text is overlaid on irregular backgrounds (the contents of a CT scan or xray) and it doesn’t get good results. Strangely enough the cloud variations handle that well.
I noticed the other thing you linked, Textract, I will check that out.
Still, I want to give fastai a go for the learning experience. I found this similar thread interesting, looks like I would need to use segmentation to extract the characters. Does anyone know how to do this? Does it require some ground-truth data, like in the camvid example in the lessons?