Quickly convert arbitrary data into/out of .png format. Example: https://i.ibb.co/qgSsgmp/out.png (is an MP3)

pnger.py

#!/usr/bin/python3
# Updated and stripped ver of https://github.com/ESultanik/bin2png Evan Sultanik
#Quickly convert arbitrary data into/out of .png format. Example: https://i.ibb.co/qgSsgmp/out.png (is an MP3)
import math
from PIL import Image
import sys

# print usage, if no arguments are given
if len(sys.argv) < 2:
    print("Usage: %s <input file> <output file>" % sys.argv[0])
    print("if <input file> is a file, will convert to png.")
    print("if <input file> is a png, will convert back to file")
    sys.exit(1)

def choose_file_dimensions(infile):
    with open(infile, 'rb') as f:
        data = f.read()
    num_bytes = len(data)
    num_pixels = int(math.ceil(float(num_bytes) / 3.0))
    sqrt = math.sqrt(num_pixels)
    sqrt_max = int(math.ceil(sqrt))
    return(sqrt_max, sqrt_max)

def png_to_file(infile, outfile, no_progress=True, verbose=False):
    img = Image.open(infile)
    with open(outfile, 'wb') as outfile:
        rgb_im = img.convert('RGB')
        pix_buffer = 0
        for row in range(img.size[1]):
            if not no_progress:
                percent = float(((row + 1) // img.size[1]) * 100)
                sys.stderr.write("\r%s%s" % (round(percent, 2), "%"))
            for col in range(img.size[0]):
                pixel = rgb_im.getpixel((col, row))
                for segment in pixel:
                    if segment == 0:
                        pix_buffer += 1
                    else:
                        if pix_buffer != 0:
                            for color in range(pix_buffer):
                                # flush the cache to the file if a non-null byte was detected
                                if sys.version_info.major >= 3:
                                    outfile.write(bytes([0]))
                                else:
                                    outfile.write(chr(0))
                            pix_buffer = 0
                        if sys.version_info.major >= 3:
                            outfile.write(bytes([segment]))
                        else:
                            outfile.write(chr(segment))

        if not no_progress:
            sys.stderr.write("\n")
        if pix_buffer != 0 and verbose:
            length = pix_buffer
            if length == 1:
                sys.stderr.write("Omitting %s zero from end of file\n" % pix_buffer)
            else:  # Why not...
                sys.stderr.write("Omitting %s zeroes from end of file\n" % pix_buffer)


def file_to_png(infile, outfile):
    reader = open(infile, 'rb')
    dimensions = choose_file_dimensions(infile)
    dim = (int(dimensions[0]), int(dimensions[1]))
    img = Image.new('RGB', dim)
    pixels = img.load()
    row = 0
    column = -1
    while True:
        b = reader.read(3)
        if not b:
            break

        column += 1
        if column >= img.size[0]:
            column = 0
            row += 1

            if row >= img.size[1]:
                raise Exception("Error: row %s is greater than maximum rows in image, %s." % (row, img.size[1]))

        color = [b[0], 0, 0]
        if len(b) > 1:
            color[1] = b[1]
        if len(b) > 2:
            color[2] = b[2]

        if not row >= img.size[1]:
            pixels[column, row] = tuple(color)

    img.save(outfile, format="PNG")
    reader.close()


#if name is main:
if __name__ == "__main__":
    # if argv[1] is a png, convert it to a file
    if sys.argv[1].endswith(".png"):
        png_to_file(sys.argv[1], sys.argv[2])
    # if argv[1] is a file, convert it to a png
    else:
        file_to_png(sys.argv[1], sys.argv[2])

A minified version (via https://python-minifier.com/) in only 58 lines:

https://gist.github.com/rocket-pig/bff10850d03806c571184dc542250a05