Specialized text to image converters can be used to print ASCII art (typically saved as either txt or ascii file) as pictures, including images saved in JPEG or PNG format. The very same "ascii to jpeg conversion" can be achieved when you open your ascii file in notepad or some other text editor and just the print screen function which will allow you to import the picture in one of the painting programs, crop it and save.
Open ASCII file Open JPEG fileA picture image editor
An online text to image conversion service