Quick script using Image Magick to convert an image to a C array

img_to_c_array.py

import os
import subprocess
from dataclasses import dataclass
from typing import List

PPM_PATH = "temp.ppm"


def to_ppm(png_path: str, resize: str = "") -> str:
    if os.path.exists(PPM_PATH):
        os.remove(PPM_PATH)

    # run convert.exe
    resize = f"-resize {resize}" if resize else ""
    subprocess.run(
        f"convert.exe -compress none {resize} {png_path} {PPM_PATH}",
        check=True)
    return PPM_PATH


@dataclass
class RGB:
    r: int
    g: int
    b: int


class PPM:
    def __init__(self):
        self.data: List[RGB] = []
        self.x = 0
        self.y = 0


def parse_ppm(path: str) -> PPM:
    with open(path, "r") as f:
        magic = f.readline().strip()
        if magic != "P3":
            raise ValueError("Invalid magic")

        ret = PPM()
        ret.x, ret.y = map(int, f.readline().strip().split(" "))

        color_depth = f.readline().strip()
        if color_depth != "255":
            raise ValueError("Invalid color depth")

        data = iter(f.read().strip().split())
        while True:
            try:
                r, g, b = map(int, (next(data), next(data), next(data)))
                ret.data.append(RGB(r, g, b))
            except StopIteration:
                break
        return ret


class PPMBlackWhite:
    def __init__(self):
        self.data: List[bool] = []
        self.x = 0
        self.y = 0


def to_ppm_blackwhite(ppm: PPM) -> PPMBlackWhite:
    ret = PPMBlackWhite()
    ret.x = ppm.x
    ret.y = ppm.y
    for rgb in ppm.data:
        ret.data.append(rgb != RGB(255, 255, 255))
    return ret


def to_c_array(ppmbw: PPMBlackWhite) -> str:
    ret = f"constexpr bool data[{ppmbw.x * ppmbw.y}]" + "{\n"
    for i, is_black in enumerate(ppmbw.data):
        if i != 0 and i % ppmbw.x == 0:
            ret += "\n"
        ret += f"{int(is_black)},"
    ret += "\n};"
    return ret


def main():
    to_ppm("test.png", resize="32x32")
    ppm = parse_ppm(PPM_PATH)
    ppmbw = to_ppm_blackwhite(ppm)
    print(to_c_array(ppmbw))


if __name__ == "__main__":
    main()