インデックスカラー画像のパレット値をGIMP Palette(.gpl)に変換

image2gpl.py

#!/usr/bin/env python
# -*- mode: python; coding: utf-8 -*-
# Last updated: <2015/12/30 20:23:02 +0900>
"""
dump GIMP Palette (.gpl) format from index color image

by mieki256
License: CC0 / Public Domain
"""
import sys
import os
from PIL import Image


def dump_palette(fn, file_output_enable=False):
    im = Image.open(fn)

    bsname = os.path.basename(fn)
    title, ext = os.path.splitext(bsname)
    path, ext = os.path.splitext(fn)

    if im.mode != "P":
        print "%s is not index color image." % (bsname)
        return

    value_mode, paldata = im.palette.getdata()
    pal = list(paldata)
    gpl_list = []
    cnt = 0
    for i in range(0, len(pal), 3):
        r = ord(pal[i])
        g = ord(pal[i + 1])
        b = ord(pal[i + 2])
        name = "#%02x%02x%02x" % (r, g, b)
        gpl_list.append("%3d %3d %3d\t%s # %d" % (r, g, b, name, cnt))
        cnt += 1

    if len(gpl_list) > 0:

        r = []
        r.append("GIMP Palette")
        r.append("Name: %s" % (title))
        r.append("Columns: 16")
        r.append("#")
        for s in gpl_list:
            r.append(s)

        gpl_fn = path + ".gpl"

        if file_output_enable:
            f = open(gpl_fn, "w")
            f.write("\n".join(r) + "\n")
            f.close()
            print
            print "Output %s" % (gpl_fn)
        else:
            for s in r:
                print s


def main():
    argv = sys.argv
    if len(argv) != 2:
        print "usage:"
        print "  python %s INPUT.png" % (os.path.basename(__file__))
        print
        print "INPUT.png is index color image file."
        sys.exit()

    # for i, v in enumerate(argv):
    #     print "%d %s" % (i, v)

    fn = argv[1]
    if os.path.exists(fn):
        dump_palette(argv[1])

if __name__ == '__main__':
    main()

usage:
python image2gpl.py INPUT.png

INPUT.png : index color image.