A CLI tool for encoding/decoding images from/to MP3 files, made as an experiment to see how MP3 compression would affect image data. Requires `pydub` and `Pillow` to be installed via `pip`.

img2mp3.py

#!/usr/bin/python3

"""
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to <https://unlicense.org>
"""

import pathlib
import argparse

import pydub
from PIL import Image

def encode_image(input_path: pathlib.Path, output_path: pathlib.Path) -> None:
    image = Image.open(input_path)
    
    image = image.convert("RGB")
    width, height = image.size

    data = bytes([value for pixel in image.getdata() for value in pixel])
    audio = pydub.AudioSegment(data, frame_rate=22050, sample_width=1, channels=1)

    audio.export(
        output_path or input_path.with_suffix(".mp3"), 
        format="mp3", 
        tags={"width": width, "height": height}
    )

def decode_image(input_path: pathlib.Path, output_path: pathlib.Path) -> None:
    audio = pydub.AudioSegment.from_file(input_path)
    audio = audio.set_sample_width(1)

    metadata = pydub.utils.mediainfo(input_path)

    width = int(metadata["TAG"]["width"])
    height = int(metadata["TAG"]["height"])

    data = audio.raw_data
    image = Image.frombytes("RGB", (width, height), data)

    image.save(output_path or input_path.with_suffix(".png"))

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Encode images into MP3 files and vice versa.")

    parser.add_argument("input_path", type=pathlib.Path, help="Path to the input file.")
    parser.add_argument("--output_path", "-o", type=pathlib.Path, help="Path to the output file. Defaults to the input file with a different extension.")

    args = parser.parse_args()

    if not args.input_path.exists():
        raise FileNotFoundError(f"input path `{args.input_path}` does not exist")

    if args.input_path.suffix == ".mp3":
        decode_image(args.input_path, args.output_path)
    else:
        encode_image(args.input_path, args.output_path)