https://github.com/diofeher/ctf-writeups/blob/master/2018-12-29-35c3/stage_diving.py

Basically you had a stego challenge in the beginning and after that you had to do Optical Character Recognition. I tried different tools but none worked, so I decided to cut the image in the size of the letters, hash the bytes, and use that as mapping.

Original writeup (https://github.com/diofeher/ctf-writeups/blob/master/2018-12-29-35c3/stage_diving.py).