I have just finished coding some basic image recognition in python to detect circles and their accuracy. I had to spend a lot of time making my picture-taker well-lit and the right size. Couple of notes:

• Through the process of trying to get lighting and everything correct to actually see the circles effectively I ended up realizing that the circles and sigils need to be very thickly outlined (in comparison to a single penstroke) which actually works out, since the anime uses magic ink (much thicker than normal)
• Based on the current average score, taking visible circle accuracy into account, I will likely be making 3 categories for the accuracy of the circle captured; Bad(<50), moderate(<80), and perfect(80+).