#!/usr/bin/env python3

"""
imgcheck - check a sequence of images for exiguous colors

usage: imgcheck baseframe imgframe...

In a sequence of images, treat the first as a baseframe and the rest
as animation images.  Report on colors not present in the baseframe.

The Python Imaging Library must be available for this tool to work
"""

import sys
try:
    from PIL import Image
except ImportError:
    print("""Please install the Python Pillow Library to run this script.
You can download it from https://pypi.python.org/pypi/Pillow
On Debian and Ubuntu you can also type in a Terminal
sudo apt-get install python-pil""", file=sys.stderr)
    sys.exit(1)

# Extract a color table list from the images
colortables = []
for filename in sys.argv[1:]:
    img = Image.open(filename).convert("RGB")
    colortable = img.getcolors()
    # getcolors() returns None if an image has more than 256 colors
    if colortable:
        colortables.append([filename, colortable])
    else:
        print("imgcheck: %s has more than 256 colors" % filename)

# Perform color table subtraction
# each color value is a (count, pixel) tuple
# get the pixel datas, which are RGB tuples, and sort them
basetable = colortables.pop(0)
basecolors = sorted(map(lambda elem: elem[1], basetable[1]))
subtracted = []
for table in colortables:
    exiguous = []
    for (n, rgb) in table[1]:
        if rgb not in basecolors:
            exiguous.append((n, rgb))
    # again, sort according to RGB data
    exiguous.sort(key=lambda elem: elem[1])
    subtracted.append((table[0], exiguous))

print("Base colors:")
print(basecolors)
for (filename, colors) in subtracted:
    print(filename + ":")
    for (n, rgb) in colors:
        print("(%3d, %3d, %3d) * %d" % (rgb[0], rgb[1], rgb[2], n))