tile_merge.py

#! /usr/bin/python
# -*- coding: UTF-8 -*-
#
# Tile merger
#
# Copyright (c) 2018 Zhuyifei1999
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# 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 OR COPYRIGHT HOLDERS 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.
#

import argparse
import collections
import itertools
import logging
import os

from PythonMagick import Image, Geometry, CompositeOperator

logger = logging.getLogger('merge')

Dimensions = collections.namedtuple('Dimensions', 'x y')  # width height


def get_tile(source, x, y):
    path = os.path.join(source, f'{x}-{y}')
    if not os.path.isfile(path) or not os.access(path, os.R_OK):
        raise IOError(f"File '{path}' doesn't exist, is not a file, "
                      'or is unreadable')

    return path


def merge(source, dest=None, size=None, tilesize=None):
    if dest is None:
        dest = os.path.join(source, 'merged.png')

    if tilesize is None:
        zeroth = Image(get_tile(source, 0, 0))
        tilesize = (zeroth.columns(), zeroth.rows())
        logger.info('Tile size not given, found '
                    f'{tilesize[0]} x {tilesize[1]}')
    tilesize = Dimensions(*tilesize)

    if size is None:
        for x in itertools.count():
            try:
                get_tile(source, x, 0)
            except IOError:
                break

        for y in itertools.count():
            try:
                get_tile(source, 0, y)
            except IOError:
                break

        numtiles = Dimensions(x, y)
        logger.warning('Image size not given, found '
                       f'{numtiles.x} x {numtiles.y} tiles, will autocrop')
    else:
        size = Dimensions(*size)
        numtiles = Dimensions(-(-size.x//tilesize.x), -(-size.y//tilesize.y))
        logger.info(f'Number of tiles: {numtiles.x} x {numtiles.y}')

    merged = Image(Geometry(
        size.x if size else numtiles.x * tilesize.x,
        size.y if size else numtiles.y * tilesize.y,
    ), 'black')

    for i in range(numtiles.x):
        for j in range(numtiles.y):
            merged.composite(
                Image(get_tile(source, i, j)),
                i * tilesize.x,
                j * tilesize.y,
                CompositeOperator.AtopCompositeOp
            )
            logger.info(f'Tile {i}-{j} merged')

    if not size:
        merged.trim()
        logger.warning(f'Autocropped to {merged.columns()} x {merged.rows()}')

    logger.info(f'Saving to {dest}')
    merged.write(dest)


def main(*args):
    parser = argparse.ArgumentParser(description='Tile merger')
    parser.add_argument('source', help='source directory')
    parser.add_argument('--dest', metavar='destination',
                        help='destination file name '
                             '(default: <source>/merged.png)')
    parser.add_argument('--size', nargs=2, type=int, metavar=('X', 'Y'),
                        help='size of an entire image')
    parser.add_argument('--tilesize', nargs=2, type=int, metavar=('X', 'Y'),
                        help='size of a single tile')
    parser.add_argument('--verbose', '-v', action='count',
                        help='increase verbosity')

    args = parser.parse_args(args or None)
    args = vars(args)

    loglevel = 30 - 10*(args.pop('verbose') or 0)

    ch = logging.StreamHandler()
    ch.setLevel(loglevel)
    logger.setLevel(loglevel)

    formatter = logging.Formatter(
        '%(asctime)s [%(levelname)s] [%(name)s] %(message)s',
        '%FT%TZ')

    ch.setFormatter(formatter)

    logger.addHandler(ch)

    merge(**args)


if __name__ == '__main__':
    main()