In case you're puzzled about the implementation of the procedure, we use the quotient to convert numbers between 0 and 127 to a number less than 1, and numbers between 128 and 255 to a number 1 and above. We then use floor to convert the numbers less than 1 to zero, and the numbers 1 and above to 1. We then multiply by 255. So, numbers between 0 and 127 get converted to 0 and numbers between 128 and 255 get converted to 255. The effect can be striking.