libervia-backend/sat/tools/images.py
2020-01-29 10:07:00 +01:00

77 lines
2.8 KiB
Python

#!/usr/bin/env python3
# SAT: a jabber client
# Copyright (C) 2009-2020 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)