ref: ce16317f33fc534a6724f5ccfd0901bf2888862b
dir: /tools/palfix.py/
#!/usr/bin/env python # -*- coding: utf-8 -*- """ Usage: python palfix.py image.png Fix the palette format of the input image. Colored images (Pokémon or trainer sprites) will become indexed, with a palette sorted {white, light color, dark color, black}. Grayscale images will become two-bit grayscale. """ from __future__ import print_function import sys from pokemontools import png def rgb8_to_rgb5(c): r, g, b = c return (r // 8, g // 8, b // 8) def rgb5_to_rgb8(c): r, g, b = c return (r * 8 + r // 4, g * 8 + g // 4, b * 8 + b // 4) def invert(c): r, g, b = c return (31 - r, 31 - g, 31 - b) def luminance(c): r, g, b = c return 0.299 * r**2 + 0.587 * g**2 + 0.114 * b**2 def rgb5_pixels(row): for x in range(0, len(row), 4): yield rgb8_to_rgb5(row[x:x+3]) def fix_pal(filename): with open(filename, 'rb') as file: width, height, data = png.Reader(file).asRGBA8()[:3] data = list(data) b_and_w = {(0, 0, 0), (31, 31, 31)} colors = set(c for row in data for c in rgb5_pixels(row)) - b_and_w if not colors: colors = {(21, 21, 21), (10, 10, 10)} elif len(colors) == 1: c = colors.pop() colors = {c, invert(c)} elif len(colors) != 2: return False palette = tuple(sorted(colors | b_and_w, key=luminance, reverse=True)) assert len(palette) == 4 data = [list(map(palette.index, rgb5_pixels(row))) for row in data] if palette == ((31, 31, 31), (21, 21, 21), (10, 10, 10), (0, 0, 0)): data = [[3 - c for c in row] for row in data] writer = png.Writer(width, height, greyscale=True, bitdepth=2, compression=9) else: palette = tuple(map(rgb5_to_rgb8, palette)) writer = png.Writer(width, height, palette=palette, bitdepth=8, compression=9) with open(filename, 'wb') as file: writer.write(file, data) return True def main(): if len(sys.argv) < 2: print('Usage:', sys.argv[0], 'pic.png', file=sys.stderr) sys.exit(1) for filename in sys.argv[1:]: if not filename.lower().endswith('.png'): print(filename, 'is not a .png file!', file=sys.stderr) elif not fix_pal(filename): print(filename, 'has too many colors!', file=sys.stderr) if __name__ == '__main__': main()