Mercurial > libervia-backend
diff sat/tools/images.py @ 3066:2cc2f65379f7
core: added imageCheck and imageResize methods:
imageCheck will give a report on image, notably it will tell if it's too big and needs to
be resized before a transfer.
imageResize will create a new image with the requested size and return a path to it.
author | Goffi <goffi@goffi.org> |
---|---|
date | Tue, 29 Oct 2019 20:38:39 +0100 |
parents | |
children | 9d0df638c8b4 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/sat/tools/images.py Tue Oct 29 20:38:39 2019 +0100 @@ -0,0 +1,77 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- + +# SAT: a jabber client +# Copyright (C) 2009-2019 Jérôme Poisson (goffi@goffi.org) + +# 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 +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# 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 <http://www.gnu.org/licenses/>. + +"""Methods to manipulate images""" + +import tempfile +from PIL import Image +from sat.core.constants import Const as C +from pathlib import Path +from twisted.internet import threads + + +def checkImage(host, path, context=C.CONTEXT_CHAT): + """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 context(str): context in which the image is transfered + @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 + """ + # TODO: context is not used yet + report = {} + image = Image.open(path) + 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] + else: + factor = max_size[1] / image.size[1] + report['recommended_size'] = [image.width*factor, image.height*factor] + else: + report['too_large'] = False + + return report + + +def _resizeImageBlocking(image_path, new_size): + im_path = Path(image_path) + im = Image.open(im_path) + resized = im.resize(new_size, Image.LANCZOS) + with tempfile.NamedTemporaryFile(suffix=im_path.suffix, delete=False) as f: + resized.save(f, format=im.format) + return Path(f.name) + + +def resizeImage(image_path, new_size): + """Resize an image to a new temporary file, and return it path + + @param image_path(str, Path): path of the original image + @param new_size(tuple[int, int]): size to use for new image + @return (Path): path of the resized file. The image at this path must be deleted + after use + """ + return threads.deferToThread(_resizeImageBlocking, image_path, new_size)