Received by email: We are playing with OCR now and checking how accurately it recognizes the texts.
It fails to recognize some important texts/urls in around 20-25% of cases.
The real pictures that our service is being spammed with are NSFW, but these test images show the same problem. The rotated text is not detected:
Another example:
Indeed, we confirmed that OCR Engine 1 does not detect this spam well.
But the solution for the user was easy: Use OCR Engine 2. It extracts the text well, even if auto-rotate is not checked. This is helpful, since the auto-rotation takes extra time. So better to keep it turned off if not required.
Update 2023: Another good OCR software for texts on tricky backgrounds (e. g. text on photos) is the new OCR engine5:
