view sat/tools/ @ 3200:5c3bf37f2202

tools (images): max_size can now be manually specified in checkImage and dest in resizeImage: `context` has been removed as it is not used and doesn't seem that useful.
author Goffi <>
date Sun, 01 Mar 2020 18:47:05 +0100
parents 8b4354b5c05f
line wrap: on
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#!/usr/bin/env python3

# SAT: a jabber client
# Copyright (C) 2009-2020 Jérôme Poisson (

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <>.

"""Methods to manipulate images"""

import tempfile
from PIL import Image
from pathlib import Path
from twisted.internet import threads

def checkImage(host, path, max_size=None):
    """Analyze image and return a report

    report will indicate if image is too large, and the recommended new size if this is
    the case
    @param host: SàT instance
    @param path(str, pathlib.Path): image to open
    @param max_size(tuple[int, int]): maximum accepted size of image
        None to use value set in config
    @return dict: report on image, with following keys:
        - too_large: true if image is oversized
        - recommended_size: if too_large is True, recommended size to use
    report = {}
    image =
    if max_size is None:
        max_size = tuple(host.memory.getConfig(None, "image_max", (1200, 720)))
    if image.size > max_size:
        report['too_large'] = True
        if image.size[0] > max_size[0]:
            factor = max_size[0] / image.size[0]
            if image.size[1] * factor > max_size[1]:
                factor = max_size[1] / image.size[1]
            factor = max_size[1] / image.size[1]
        report['recommended_size'] = [int(image.width*factor), int(image.height*factor)]
        report['too_large'] = False

    return report

def _resizeImageBlocking(image_path, new_size, dest=None):
    im_path = Path(image_path)
    im =
    resized = im.resize(new_size, Image.LANCZOS)

    if dest is None:
        dest = tempfile.NamedTemporaryFile(suffix=im_path.suffix, delete=False)
    elif isinstance(dest, Path):
        dest ='wb')

    with dest as f:, format=im.format)

    return Path(

def resizeImage(image_path, new_size, dest=None):
    """Resize an image to a new file, and return its path

    @param image_path(str, Path): path of the original image
    @param new_size(tuple[int, int]): size to use for new image
    @param dest(None, Path, file): where the resized image must be stored, can be:
        - None: use a temporary file
        - Path: path to the file to create/overwrite
        - file: a file object which must be opened for writing in binary mode
    @return (Path): path of the resized file.
        The image at this path should be deleted after use
    return threads.deferToThread(_resizeImageBlocking, image_path, new_size, dest)