Failure to detect chessboard in images that are chessboards

[rayoh123]

https://i.redd.it/yrl4gdw8iml31.jpg
https://i.redd.it/n66usnoq38m31.png
https://i.redd.it/nq65jjiohfm31.png

Why can't the bot detect a chessboard in the images above?

import subprocess, os
r = subprocess.check_output("cd C:\Users\Raymond\Desktop\Chess Bot\tensorflow_chessbot-chessfenbot && tensorflow_chessbot.py --url https://i.redd.it/yrl4gdw8iml31.jpg", shell=True)

the code above crashes and the traceback states that there is "no chessboard detected"

[ddugovic]

I think this bot relies on there being a high contrast between the square colors.

[Elucidation]

As ddugovic said, moving under #42