#!/bin/sh set -xe circle_coordinates="256,256,256" background_color="white" foreground_color="black" convert -size 512x512 \ "xc:${backgrond_color}" \ -fill "${foreground_color}" \ -draw "circle ${circle_coordinates},32" \ -fill "${background_color}" \ -draw "circle ${circle_coordinates},96" \ "${1}.png" convert "${1}.png" -resize "50%" "${1}-medium.png" convert "${1}.png" -resize "25%" "${1}-small.png" convert "${1}-small.png" \ -level -10%,12% \ -ordered-dither o8x8 \ "${1}-dithered.png"