#!/bin/sh

PATH=${PWD%/code*}/code:$PATH

# Initial image is a 16 pixel wide gradient with (if correct)
# all 4-bit shades of grey.
priforgepng -d 4 glr -s 16 |
  prichunkpng --transparent '#5' - |
  pipcolours - | pripnglsch |
  grep IHDR |
  grep -i -q 00000010000000010804000000