dotpixels.py

from PIL import Image, ImageDraw
import math


def main():
    im = Image.open('city.png').convert('RGB')
    out = Image.new('RGB', im.size)

    dotw = 16
    doth = 16
    dot_radius = min(dotw, doth) // 2

    dots_horiz = math.ceil(im.width / dotw)
    dots_vert = math.ceil(im.height / doth)

    im.thumbnail((dots_horiz, dots_vert), Image.Resampling.NEAREST)
    im = im.quantize(128).convert('RGB')

    draw = ImageDraw.Draw(out)
    for y in range(im.height):
        for x in range(im.width):
            pixel = im.getpixel((x, y))
            cx = x * dotw + dotw // 2
            cy = y * doth + doth // 2
            cr = dot_radius * 0.8
            draw.ellipse((cx - cr, cy - cr, cx + cr, cy + cr), fill=pixel)

    # out.show()
    out.save('city-out.png')


if __name__ == '__main__':
    main()