slice_image.py

import PIL
from PIL import Image
import sys

# Makes a lambda that only accepts given colors (ie, returns black for them, white otherwise)
def make_transform(accepted_colors):
    return (lambda color: 0 if color in accepted_colors else 255)

def slice_image(in_img):
    in_img = in_img.convert('L').transpose(Image.ROTATE_270)

    animated = in_img.width == 96

    out_img = Image.new('L', (16,768))

    # A bit fugly, but it just separates the two transforms and makes a chunk list out of them.
    left_in_img = in_img.point(make_transform([0,128]))
    right_in_img = in_img.point(make_transform([0,64]))
    lchunks = [right_in_img.crop((in_img.width-((i+1)*8),0,in_img.width-(i*8),64)) for i in range(0, 12 if animated else 6)]
    rchunks = [left_in_img.crop((in_img.width-((i+1)*8),0,in_img.width-(i*8),64)) for i in range(0, 12 if animated else 6)]

    for i in range(0,12 if animated else 6):
        out_img.paste(lchunks[i], (0, i*64))
        out_img.paste(rchunks[i], (8, i*64))
        
        if not animated:
            out_img.paste(lchunks[i], (0, (i+6)*64))
            out_img.paste(rchunks[i], (8, (i+6)*64))
    
    return out_img
        
if __name__ == '__main__':
    if len(sys.argv) < 2:
        print("Correct syntax: slice_image.py in-file [out-file]")
        sys.exit()
        
    with Image.open(sys.argv[1]) as in_img:
        out_img = slice_image(in_img)
        
    if len(sys.argv) > 2:
        out_img.save(sys.argv[2], "PNG")
    else:
        out_img.show()