For best results, make sure that you include the border of the chessboard and crop close to it.If certain parts of the diagram are blurry or too hard to read, the algorithm makes the best guess instead of giving up. You can always correct mistakes in the Lichess link.
Presently the code does well with the three fonts shown and those close enough to it. If you have examples of books and images that don't work well, please let me know at gophergoon at gmail
Chessputzer was inspired by Fenbot but intended for scanned images with noise and artifacts.
How it works(coming soon)