#!/usr/bin/python -tt
#
# Read a BOM radar GIF named on the command line, emit a transparent
# PNG on standard output - suppress sea, land and the lightest rainfall.
#       - Cameron Simpson <cs@zip.com.au>
#

import sys
from PIL import Image
import cs.hier
im=sys.argv[1]
raw=Image.open(im)
IM=Image.new("RGBA",(512,496))
IM.paste(raw, None)
for x in range(512):
  for y in range(496):
    p=IM.getpixel((x,y))
    rgb=p[:3]
    if rgb in (
                (  0,   0,   0),
                (245, 245, 255),
                (195, 217, 235),
                (210, 161, 85),
                (216, 178, 100),
                (221, 198, 118),
                (226, 203, 140),
                (231, 220, 189),
              ):
      IM.putpixel((x,y),(0,0,0,0))

IM.save("/dev/fd/1","PNG")