Generate a node.js script that prints an image to the console using chalk. Requires pillow.

png2console

#!/usr/bin/env python3

import sys
from itertools import islice
from PIL import Image

PIXEL = '▄'

# The amount an image needs to be scaled to look good in terminal
TERM_RATIO = 0.8276


def main():
    im = Image.open(sys.argv[1])
    im = im.convert('RGB')
    im = scale_image(im)
    width, height = im.size

    fgcolors = set()
    bgcolors = set()

    rows = []

    for [row1, row2] in every_two_rows(im.getdata(), width):
        log_row = []
        for pair, i in dedupe(zip(row1, row2)):
            bg, fg = pair
            bgcolors.add(bg)
            fgcolors.add(fg)
            log_row.append((pair, i))
        rows.append(log_row)

    fgcolors = sorted(list(fgcolors))
    bgcolors = sorted(list(bgcolors))

    fgmap = {}
    bgmap = {}

    def do_map(l, m, n):
        for i, c in enumerate(l):
            name = f'{n}{i}'
            args = ', '.join(map(str, c))
            if n == 'bg':
                print(f'const {name} = chalk.bgRgb({args});')
            else:
                print(f'const {name} = chalk.rgb({args});')
            m[c] = name

    print("const chalk = require('chalk');")
    print()

    do_map(fgcolors, fgmap, 'fg')
    do_map(bgcolors, bgmap, 'bg')

    print()

    for row in rows:
        parts = []
        for (bg, fg), count in row:
            bgfn = bgmap[bg]
            fgfn = fgmap[fg]
            if bgfn == fgfn:
                parts.append(f"{bgfn}(' ')")
            else:
                parts.append(f"{bgfn}({fgfn}('{PIXEL*count}'))")
        joined = ''.join(map(lambda x: f'${{{x}}}', parts))
        print(f"console.log(`{joined}`);")


def dedupe(data):
    same = []
    for d in data:
        if not same or len(set(same + [d])) == 1:
            same.append(d)
        else:
            yield same[0], len(same)
            same = [d]
    if same:
        yield same[0], len(same)


def every_two_rows(data, width):
    curr_row = []
    rows = []

    for d in data:
        curr_row.append(d)
        if len(curr_row) == width:
            rows.append(curr_row)
            curr_row = []
        if len(rows) == 2:
            yield rows
            rows = []

    if len(rows) == 1:
        rows.append([(0,0,0)] * width)
        yield rows


def scale_image(img):
    # first, resize due to terminal scaling
    width, height = img.size

    if width > 64:
        scale = 64/width
        width = int(width*scale)
        height = int(height*scale)
        img = img.resize((width, height))

    return img.resize((width, int(height * TERM_RATIO)), Image.BICUBIC)


main()