As far as I know, you cant convert jpgs to ascii, but it looks like that is what has been done.
Because, I have NEVER seen work like this before.
I remember ANSI and ASCII art from back in the early 90's. We had our BBS's decorated with them. Ah those were the days. I used a program called Aciddraw. It used ANSI, and ASCII, and you had to place each indidvidual charactar in its respective place. Thats the impressive thing about this. I kinda look at them as modern day mosaics.