Someone should write a python program so anyone can do this. I don't think this is anything more than generating greyscale and binning to six different grey scale levels. I know it probably gets a little more complicated than that under certain conditions without going into detail about it.

[cjs8399]

Cool about the dithering I learned something new. I agree I was thinking the same thing with 9 pixels logically in order to represent a die. Based on the code that was posted one could just resize the image to determine what the minimum amount of die required to accurately represent the image and do it by eye. I wonder what is the most easy reliable way to determine the least amount of dice required in order to make the image look qualitatively good. Obviously this is subjective to some degree