bitmapToASCII.py

#!/usr/local/bin/python2
# encoding: UTF-8

import sys
import argparse

from PIL import Image

class conf(object):
    pad  = True
    bw   = False
    file = None

class Color(object):
    CLEAR = "\033[0m"
    ALPHA_LIMIT = 1

    GREYSCALE_BEGIN = 232
    COLOR_BEGIN     = 16

    def __init__(self, rgba):
        r, g, b, a = rgba
        self.r = r
        self.g = g
        self.b = b
        self.a = a

    def escape(self, value):
        return "\033[48;5;%dm" % value

    def code(self):
        is_clear = self.a < self.ALPHA_LIMIT
        if   is_clear: return self.CLEAR
        elif conf.bw:  return self.bw_code()
        else:          return self.color_code()

    def color_code(self):
        ratio = 5.0 / 255.0
        r = int(round(ratio * self.r))
        g = int(round(ratio * self.g))
        b = int(round(ratio * self.b))
        return self.escape(
            r * 6 * 6 +
            g * 6 +
            b +
            self.COLOR_BEGIN
        )

    def bw_code(self):
        ratio = 24.0 / 255.0
        avg   = (self.r + self.g + self.b)/3.0
        shade = int(round(ratio * avg))
        return self.escape(shade + self.GREYSCALE_BEGIN)

def calc_size(img):
    iw, ih = img.size
    aspect = float(iw) / float(ih) # image aspect
    font   = 2.0 # font aspect
    h = ih
    w = h * aspect * font
    w = int(round(w))

    return (w, h)

def main(**kwargs):
    img  = Image.open(conf.file)
    w, h = calc_size(img)
    img  = img.resize(calc_size(img))
    img  = img.convert("RGBA")
    pix  = img.load()

    write = sys.stdout.write

    if conf.pad:
        write("\n")
    for y in xrange(h):
        sys.stdout.write(Color.CLEAR)
        if conf.pad:
            write(" ")
            write(" ")
        for x in xrange(w):
            rgba = pix[x, y]
            code = Color(rgba).code()
            write(code)
            write(" ")
        write(Color.CLEAR)
        write("\n")

parser = argparse.ArgumentParser(
    description="Print ANSI art for an image to standard output."
)
parser.add_argument(
    "file",
    type=str,
    help="File to convert"
)
parser.add_argument(
    "--bw",
    action="store_const",
    const=True,
    default=False,
    help="Enable greyscale mode"
)
parser.add_argument(
    "--no-pad",
    action="store_const",
    const=True,
    default=False,
    help="Disable padding"
)
args = parser.parse_args()
conf.bw   = args.bw
conf.pad  = not args.no_pad
conf.file = args.file
main()