Convert image to monochrome c bitmaps array.

convert_to_eink_bitmaps.py

import argparse
import logging
import os.path as path
from PIL import Image
import numpy as np
logger = logging.getLogger(__name__)
logging.basicConfig(format='%(name)s::%(levelname)-8s: %(message)s')


class VerbosityParsor(argparse.Action):
    """ accept debug, info, ... or theirs corresponding integer value formatted as string."""

    def __call__(self, parser, namespace, values, option_string=None):
        assert isinstance(values, str)
        try:  # in case it represent an int, directly get it
            values = int(values)
        except ValueError:  # else ask logging to sort it out
            values = logging.getLevelName(values.upper())
        setattr(namespace, self.dest, values)


def convert(input_filepath, output_filepath, rotation=0):
    filename = path.basename(path.splitext(input_filepath)[0])
    image = Image.open(input_filepath)  # open colour image
    image = image.convert('1')  # convert image to black and white
    rotation_angles = {1: 90, 2: 180, 3: 270}
    if rotation in rotation_angles:
        image = image.rotate(rotation_angles[rotation], expand=False)
    width, height = image.size
    # check dimensions are multiple of 8 bits
    if any((s % 8) != 0 for s in image.size):
        logger.warning(f'dimensions not multiple of 8 may cause problems')
    bitmap = np.array(image).flatten()
    if not (len(bitmap) % 8 == 0):
        raise ValueError('')
    # repack 8 bits as chars
    bitmap = bitmap.reshape((-1, 8))
    bitmap = np.packbits(bitmap, axis=1).flatten()
    # make pack of 12 chars for a nice formatting
    bits = bitmap.tolist()
    nb_bits = len(bits)
    nb_cols = int(12)
    nb_tail = nb_cols - (nb_bits % nb_cols) if nb_bits % nb_cols != 0 else 0
    bits = bits + [None] * nb_tail
    bitmap = np.array(bits).reshape((-1, nb_cols))

    with open(output_filepath, 'wt') as fout:
        fout.write(f'static const size_t bitmap_{filename}_width = {width};\n')
        fout.write(f'static const size_t bitmap_{filename}_height  = {height};\n')
        fout.write(f'static const uint8_t bitmap_{filename}_data[{nb_bits}] = ')
        fout.write('{\n')
        fout.write(',\n'.join((', '.join(f'0x{value:02x}' for value in line if value is not None)
                               for line in bitmap)))
        fout.write('\n};\n')


def main():
    parser = argparse.ArgumentParser(description='Convert image to monochrome c bitmaps array.')
    parser_verbosity = parser.add_mutually_exclusive_group()
    parser_verbosity.add_argument(
        '-v', '--verbose', nargs='?', default=logging.INFO, const=logging.DEBUG, action=VerbosityParsor,
        help='verbosity level (debug, info, warning, critical, ... or int value) [warning]')
    parser_verbosity.add_argument(
        '-q', '--silent', '--quiet', action='store_const', dest='verbose', const=logging.CRITICAL)
    parser.add_argument('-i', '--input', required=True, help='input')
    parser.add_argument('-o', '--output', help='output [input.h]')
    parser.add_argument('-r', '--rotation', type=int, choices=range(4), default=0, help='output [input.h]')

    args = parser.parse_args()
    logger.setLevel(args.verbose)

    try:
        args.input = path.abspath(args.input)
        if not args.output:
            args.output = path.splitext(args.input)[0] + '.h'
        convert(args.input, args.output, rotation=args.rotation)

    except Exception as e:
        logger.critical(e)
        if args.verbose <= logging.DEBUG:
            raise


if __name__ == '__main__':

    main()