# ContentDB # Copyright (C) 2018-21 rubenwardy # # 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 . from flask import abort, send_file, Blueprint, current_app import os from PIL import Image bp = Blueprint("thumbnails", __name__) ALLOWED_RESOLUTIONS = [(100, 67), (270, 180), (350, 233), (1100, 520)] ALLOWED_EXTENSIONS = {"png", "webp", "jpg"} def mkdir(path): assert path != "" and path is not None try: if not os.path.isdir(path): os.mkdir(path) except FileExistsError: pass def resize_and_crop(img_path, modified_path, size): with Image.open(img_path) as img: # Get current and desired ratio for the images img_ratio = img.size[0] / float(img.size[1]) desired_ratio = size[0] / float(size[1]) # Is more portrait than target, scale and crop if desired_ratio > img_ratio: img = img.resize((int(size[0]), int(size[0] * img.size[1] / img.size[0])), Image.BICUBIC) box = (0, (img.size[1] - size[1]) / 2, img.size[0], (img.size[1] + size[1]) / 2) img = img.crop(box) # Is more landscape than target, scale and crop elif desired_ratio < img_ratio: img = img.resize((int(size[1] * img.size[0] / img.size[1]), int(size[1])), Image.BICUBIC) box = ((img.size[0] - size[0]) / 2, 0, (img.size[0] + size[0]) / 2, img.size[1]) img = img.crop(box) # Is exactly the same ratio as target else: img = img.resize(size, Image.BICUBIC) if modified_path.endswith(".jpg") and img.mode != "RGB": img = img.convert("RGB") img.save(modified_path, lossless=True) def find_source_file(img): upload_dir = current_app.config["UPLOAD_DIR"] source_filepath = os.path.join(upload_dir, img) if os.path.isfile(source_filepath): return source_filepath period = source_filepath.rfind(".") start = source_filepath[:period] ext = source_filepath[period + 1:] if ext not in ALLOWED_EXTENSIONS: abort(404) for other_ext in ALLOWED_EXTENSIONS: other_path = f"{start}.{other_ext}" if ext != other_ext and os.path.isfile(other_path): return other_path abort(404) @bp.route("/thumbnails//") def make_thumbnail(img, level): if level > len(ALLOWED_RESOLUTIONS) or level <= 0: abort(403) w, h = ALLOWED_RESOLUTIONS[level - 1] thumbnail_dir = current_app.config["THUMBNAIL_DIR"] mkdir(thumbnail_dir) output_dir = os.path.join(thumbnail_dir, str(level)) mkdir(output_dir) cache_filepath = os.path.join(output_dir, img) if not os.path.isfile(cache_filepath): source_filepath = find_source_file(img) resize_and_crop(source_filepath, cache_filepath, (w, h)) res = send_file(cache_filepath) res.cache_control.max_age = 7*24*60*60 return res