improve cover contrast

poetry.lock

@@ -60,11 +60,11 @@ cffi = ">=1.0.0"
 
 [[package]]
 name = "certifi"
-version = "2022.5.18"
+version = "2022.5.18.1"
 description = "Python package for providing Mozilla's CA Bundle."
 category = "main"
 optional = false
-python-versions = ">=3.5"
+python-versions = ">=3.6"
 
 [[package]]
 name = "cffi"
@@ -220,7 +220,7 @@ testing = ["mock (>=2.0.0)"]
 
 [[package]]
 name = "feedparser"
-version = "6.0.8"
+version = "6.0.9"
 description = "Universal feed parser, handles RSS 0.9x, RSS 1.0, RSS 2.0, CDF, Atom 0.3, and Atom 1.0 feeds"
 category = "main"
 optional = false
@@ -273,7 +273,7 @@ export = ["jinja2 (>=2.7,<3)"]
 
 [[package]]
 name = "identify"
-version = "2.5.0"
+version = "2.5.1"
 description = "File identification library for Python"
 category = "dev"
 optional = false
@@ -845,8 +845,8 @@ brotlicffi = [
     {file = "brotlicffi-1.0.9.2.tar.gz", hash = "sha256:0c248a68129d8fc6a217767406c731e498c3e19a7be05ea0a90c3c86637b7d96"},
 ]
 certifi = [
-    {file = "certifi-2022.5.18-py3-none-any.whl", hash = "sha256:8d15a5a7fde18536a249c49e07e8e462b8fc13de21b3c80e8a68315dfa227c99"},
-    {file = "certifi-2022.5.18.tar.gz", hash = "sha256:6ae10321df3e464305a46e997da41ea56c1d311fb9ff1dd4e04d6f14653ec63a"},
+    {file = "certifi-2022.5.18.1-py3-none-any.whl", hash = "sha256:f1d53542ee8cbedbe2118b5686372fb33c297fcd6379b050cca0ef13a597382a"},
+    {file = "certifi-2022.5.18.1.tar.gz", hash = "sha256:9c5705e395cd70084351dd8ad5c41e65655e08ce46f2ec9cf6c2c08390f71eb7"},
 ]
 cffi = [
     {file = "cffi-1.15.0-cp27-cp27m-macosx_10_9_x86_64.whl", hash = "sha256:c2502a1a03b6312837279c8c1bd3ebedf6c12c4228ddbad40912d671ccc8a962"},
@@ -988,8 +988,8 @@ django-rq = [
     {file = "django_rq-2.5.1-py2.py3-none-any.whl", hash = "sha256:7be1e10e7091555f9f36edf100b0dbb205ea2b98683d74443d2bdf3c6649a03f"},
 ]
 feedparser = [
-    {file = "feedparser-6.0.8-py3-none-any.whl", hash = "sha256:1b7f57841d9cf85074deb316ed2c795091a238adb79846bc46dccdaf80f9c59a"},
-    {file = "feedparser-6.0.8.tar.gz", hash = "sha256:5ce0410a05ab248c8c7cfca3a0ea2203968ee9ff4486067379af4827a59f9661"},
+    {file = "feedparser-6.0.9-py3-none-any.whl", hash = "sha256:a522b2b81f3914a74ae44161a341940f74811bd29be5b4c2a689e6e6be51cd39"},
+    {file = "feedparser-6.0.9.tar.gz", hash = "sha256:dad42e7beaec55f99c08b2b0cf7288bc7cfd24b6f72c8ef85478bcb55648cd42"},
 ]
 filelock = [
     {file = "filelock-3.7.0-py3-none-any.whl", hash = "sha256:c7b5fdb219b398a5b28c8e4c1893ef5f98ece6a38c6ab2c22e26ec161556fed6"},
@@ -1010,8 +1010,8 @@ honcho = [
     {file = "honcho-1.1.0.tar.gz", hash = "sha256:c5eca0bded4bef6697a23aec0422fd4f6508ea3581979a3485fc4b89357eb2a9"},
 ]
 identify = [
-    {file = "identify-2.5.0-py2.py3-none-any.whl", hash = "sha256:3acfe15a96e4272b4ec5662ee3e231ceba976ef63fd9980ed2ce9cc415df393f"},
-    {file = "identify-2.5.0.tar.gz", hash = "sha256:c83af514ea50bf2be2c4a3f2fb349442b59dc87284558ae9ff54191bff3541d2"},
+    {file = "identify-2.5.1-py2.py3-none-any.whl", hash = "sha256:0dca2ea3e4381c435ef9c33ba100a78a9b40c0bab11189c7cf121f75815efeaa"},
+    {file = "identify-2.5.1.tar.gz", hash = "sha256:3d11b16f3fe19f52039fb7e39c9c884b21cb1b586988114fbe42671f03de3e82"},
 ]
 idna = [
     {file = "idna-3.3-py3-none-any.whl", hash = "sha256:84d9dd047ffa80596e0f246e2eab0b391788b0503584e8945f2368256d2735ff"},

ucast/__init__.py

@@ -0,0 +1,3 @@
+__version__ = "0.0.1"
+
+default_app_config = "ucast.apps.UcastConfig"

ucast/apps.py

@@ -4,3 +4,8 @@ from django.apps import AppConfig
 class UcastConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "ucast"
+
+    def ready(self):
+        from ucast.tasks import download
+
+        download.schedule_update_channels()

ucast/service/cover.py

@@ -1,4 +1,5 @@
 import math
+import random
 from importlib import resources
 from pathlib import Path
 from typing import List, Literal, Optional, Tuple
@@ -6,7 +7,7 @@ from typing import List, Literal, Optional, Tuple
 import wcag_contrast_ratio
 from colorthief import ColorThief
 from fonts.ttf import SourceSansPro
-from PIL import Image, ImageDraw, ImageFilter, ImageFont
+from PIL import Image, ImageDraw, ImageEnhance, ImageFilter, ImageFont
 
 from ucast.service import typ
 
@@ -16,6 +17,7 @@ CoverStyle = Literal["blur", "gradient"]
 
 CHAR_ELLIPSIS = "…"
 COVER_WIDTH = 500
+MIN_CONTRAST = 4.5
 
 
 def _split_text(
@@ -30,7 +32,7 @@ def _split_text(
     :param text: Input text
     :param font: Pillow ImageFont
     :param line_spacing: Line spacing [px]
-    :return:
+    :return: List of lines
     """
     if height < font.size:
         return []
@@ -99,7 +101,6 @@ def _draw_text_box(
     :param color: Text color
     :param line_spacing: Line spacing [px]
     :param vertical_center: Center text vertically in the box
-    :return:
     """
     x_tl, y_tl, x_br, y_br = box
     height = y_br - y_tl
@@ -144,7 +145,11 @@ def _interpolate_color(color_from: typ.Color, color_to: typ.Color, steps: int):
         yield [round(f + det * i) for f, det in zip(color_from, det_co)]
 
 
-def _get_text_color(bg_color) -> typ.Color:
+def _color_to_float(color: typ.Color) -> tuple[float, ...]:
+    return tuple(c / 255 for c in color)
+
+
+def _get_text_color(bg_color: typ.Color) -> typ.Color:
     """
     Return the text color (black or white) with the largest contrast
     to a given background color.
@@ -152,26 +157,19 @@ def _get_text_color(bg_color) -> typ.Color:
     :param bg_color: Background color
     :return: Text color
     """
-    color_decimal = tuple([c / 255 for c in bg_color])
-    c_blk = wcag_contrast_ratio.rgb((0, 0, 0), color_decimal)
-    c_wht = wcag_contrast_ratio.rgb((1, 1, 1), color_decimal)
+    color_float = _color_to_float(bg_color)
+    c_blk = wcag_contrast_ratio.rgb((0, 0, 0), color_float)
+    c_wht = wcag_contrast_ratio.rgb((1, 1, 1), color_float)
     if c_wht > c_blk:
         return 255, 255, 255
     return 0, 0, 0
 
 
-def _get_baseimage(
-    thumbnail: Image.Image,
-    top_color: typ.Color,
-    bottom_color: typ.Color,
-    style: CoverStyle,
-):
+def _get_baseimage(thumbnail: Image.Image, style: CoverStyle):
     """
     Return the background image for the cover.
 
     :param thumbnail: Thumbnail image object
-    :param top_color: Top color of the thumbnail image
-    :param bottom_color: Bottom color of the thumbnail image
     :param style: Style of the cover image
     :return: Base image
     """
@@ -179,6 +177,15 @@ def _get_baseimage(
 
     if style == COVER_STYLE_GRADIENT:
         # Thumbnail with color gradient background
+
+        # Get dominant colors from the top and bottom 20% of the thumbnail image
+        top_part = thumbnail.crop((0, 0, COVER_WIDTH, int(thumbnail.height * 0.2)))
+        bottom_part = thumbnail.crop(
+            (0, int(thumbnail.height * 0.8), COVER_WIDTH, thumbnail.height)
+        )
+        top_color = _get_dominant_color(top_part)
+        bottom_color = _get_dominant_color(bottom_part)
+
         cover_draw = ImageDraw.Draw(cover)
 
         for i, color in enumerate(
@@ -217,27 +224,139 @@ def _resize_thumbnail(thumbnail: Image.Image) -> Image.Image:
     )
 
 
+def _prepare_text_background(
+    base_img: Image.Image, bboxes: List[Tuple[int, int, int, int]]
+) -> Tuple[Image.Image, typ.Color]:
+    """
+    Return the preferred text color (black or white) and darken
+    the image if necessary
+
+    :param base_img: Image object
+    :param bboxes: Text boxes
+    :return: Updated image, text color
+    """
+    rng = random.Random()
+    rng.seed(0x9B38D30461B7F0E6)
+
+    min_contrast_bk = 22
+    min_contrast_wt = 22
+    worst_color_wt = None
+
+    def corr_x(x: int) -> int:
+        return min(max(0, x), base_img.width)
+
+    def corr_y(y: int) -> int:
+        return min(max(0, y), base_img.height)
+
+    for bbox in bboxes:
+        x_tl, y_tl, x_br, y_br = bbox
+        x_tl = corr_x(x_tl)
+        y_tl = corr_y(y_tl)
+        x_br = corr_x(x_br)
+        y_br = corr_y(y_br)
+
+        height = y_br - y_tl
+        width = x_br - x_tl
+
+        for _ in range(math.ceil(width * height * 0.01)):
+            target_pos = (rng.randint(x_tl, x_br - 1), rng.randint(y_tl, y_br - 1))
+            img_color = base_img.getpixel(target_pos)
+            img_color_float = _color_to_float(img_color)
+
+            ct_bk = wcag_contrast_ratio.rgb((0, 0, 0), img_color_float)
+            ct_wt = wcag_contrast_ratio.rgb((1, 1, 1), img_color_float)
+
+            if ct_bk < min_contrast_bk:
+                min_contrast_bk = ct_bk
+
+            if ct_wt < min_contrast_wt:
+                worst_color_wt = img_color
+                min_contrast_wt = ct_wt
+
+    if min_contrast_bk >= MIN_CONTRAST:
+        return base_img, (0, 0, 0)
+    if min_contrast_wt >= MIN_CONTRAST:
+        return base_img, (255, 255, 255)
+
+    pixel = Image.new("RGB", (1, 1), worst_color_wt)
+
+    for i in range(1, 100):
+        brightness_f = 1 - i / 100
+        contrast_f = 1 - i / 1000
+
+        pixel_c = ImageEnhance.Brightness(pixel).enhance(brightness_f)
+        pixel_c = ImageEnhance.Contrast(pixel_c).enhance(contrast_f)
+        new_color = pixel_c.getpixel((0, 0))
+
+        if (
+            wcag_contrast_ratio.rgb((1, 1, 1), _color_to_float(new_color))
+            >= MIN_CONTRAST
+        ):
+            new_img = ImageEnhance.Brightness(base_img).enhance(brightness_f)
+            new_img = ImageEnhance.Contrast(new_img).enhance(contrast_f)
+            return new_img, (255, 255, 255)
+
+    return base_img, (255, 255, 255)
+
+
 def _draw_text_avatar(
     cover: Image.Image,
     avatar: Optional[Image.Image],
     title: str,
     channel: str,
-    top_color: typ.Color,
-    bottom_color: typ.Color,
-):
-    cover_draw = ImageDraw.Draw(cover)
-
+) -> Image.Image:
     # Add channel avatar
     avt_margin = 0
     avt_size = 0
 
-    tn_16_9_height = int(COVER_WIDTH / 16 * 9)
-    tn_16_9_margin = int((COVER_WIDTH - tn_16_9_height) / 2)
+    tn_16_9_height = int(COVER_WIDTH / 16 * 9)  # typical: 281
+    tn_16_9_margin = int((COVER_WIDTH - tn_16_9_height) / 2)  # typical: 110
 
     if avatar:
-        avt_margin = int(tn_16_9_margin * 0.05)
-        avt_size = tn_16_9_margin - 2 * avt_margin
+        avt_margin = int(tn_16_9_margin * 0.05)  # typical: 14
+        avt_size = tn_16_9_margin - 2 * avt_margin  # typical: 82
 
+    # Add text
+    text_margin_x = 16
+    text_margin_topleft = avt_margin + avt_size + text_margin_x  # typical: 112
+    text_vertical_offset = -17
+    text_line_space = -4
+
+    fnt = ImageFont.truetype(SourceSansPro, 50)
+    top_text_box = (  # typical: (112, -17, 484, 110)
+        text_margin_topleft,
+        text_vertical_offset,
+        COVER_WIDTH - text_margin_x,
+        tn_16_9_margin,
+    )
+    bottom_text_box = (  # typical: (16, 373, 484, 500)
+        text_margin_x,
+        COVER_WIDTH - tn_16_9_margin + text_vertical_offset,
+        COVER_WIDTH - text_margin_x,
+        COVER_WIDTH,
+    )
+
+    cover, text_color = _prepare_text_background(cover, [top_text_box, bottom_text_box])
+    cover_draw = ImageDraw.Draw(cover)
+
+    _draw_text_box(
+        cover_draw,
+        top_text_box,
+        channel,
+        fnt,
+        text_color,
+        text_line_space,
+    )
+    _draw_text_box(
+        cover_draw,
+        bottom_text_box,
+        title,
+        fnt,
+        text_color,
+        text_line_space,
+    )
+
+    if avatar:
         avt = avatar.resize((avt_size, avt_size), Image.LANCZOS)
 
         circle_mask = Image.new("L", (avt_size, avt_size))
@@ -246,42 +365,7 @@ def _draw_text_avatar(
 
         cover.paste(avt, (avt_margin, avt_margin), circle_mask)
 
-    # Add text
-    text_margin_x = 16
-    text_margin_topleft = avt_margin + avt_size + text_margin_x
-    text_vertical_offset = -17
-    text_line_space = -4
-
-    fnt = ImageFont.truetype(SourceSansPro, 50)
-    top_text_color = _get_text_color(top_color)
-    bottom_text_color = _get_text_color(bottom_color)
-
-    _draw_text_box(
-        cover_draw,
-        (
-            text_margin_topleft,
-            text_vertical_offset,
-            COVER_WIDTH - text_margin_x,
-            tn_16_9_margin,
-        ),
-        channel,
-        fnt,
-        top_text_color,
-        text_line_space,
-    )
-    _draw_text_box(
-        cover_draw,
-        (
-            text_margin_x,
-            COVER_WIDTH - tn_16_9_margin + text_vertical_offset,
-            COVER_WIDTH - text_margin_x,
-            COVER_WIDTH,
-        ),
-        title,
-        fnt,
-        bottom_text_color,
-        text_line_space,
-    )
+    return cover
 
 
 def _create_cover_image(
@@ -303,20 +387,14 @@ def _create_cover_image(
     """
     tn = _resize_thumbnail(thumbnail)
 
-    # Get dominant colors from the top and bottom 20% of the thumbnail image
-    top_part = tn.crop((0, 0, COVER_WIDTH, int(tn.height * 0.2)))
-    bottom_part = tn.crop((0, int(tn.height * 0.8), COVER_WIDTH, tn.height))
-    top_color = _get_dominant_color(top_part)
-    bottom_color = _get_dominant_color(bottom_part)
+    cover = _get_baseimage(tn, style)
 
-    cover = _get_baseimage(tn, top_color, bottom_color, style)
+    cover = _draw_text_avatar(cover, avatar, title, channel)
 
     # Insert thumbnail image in the middle
     tn_margin = int((COVER_WIDTH - tn.height) / 2)
     cover.paste(tn, (0, tn_margin))
 
-    _draw_text_avatar(cover, avatar, title, channel, top_color, bottom_color)
-
     return cover
 
 
@@ -332,7 +410,7 @@ def _create_blank_cover_image(
     yt_icon_y_top = int((COVER_WIDTH - yt_icon.height) / 2)
     cover.paste(yt_icon, (yt_icon_x_left, yt_icon_y_top))
 
-    _draw_text_avatar(cover, avatar, title, channel, bg_color, bg_color)
+    _draw_text_avatar(cover, avatar, title, channel)
 
     return cover
 

ucast/service/youtube.py

@@ -9,7 +9,6 @@ from typing import List, Optional
 
 import feedparser
 import requests
-from django.conf import settings
 from mutagen import id3
 from yt_dlp import YoutubeDL
 
@@ -291,9 +290,7 @@ def get_channel_videos_from_scraper(
     """
     videos = []
 
-    for item in scrapetube.get_channel(
-        channel_url_from_id(channel_id), limit, settings.YOUTUBE_SCRAPE_DELAY
-    ):
+    for item in scrapetube.get_channel(channel_url_from_id(channel_id), limit):
         video_id = item.get("videoId")
         if not video_id:
             logging.warning(

ucast/tasks/download.py

@@ -1,6 +1,8 @@
 import os
+from datetime import datetime
 
 import django_rq
+from django.conf import settings
 from django.utils import timezone
 
 from ucast.models import Channel, Video
@@ -118,6 +120,15 @@ def import_channel(channel_id: str, limit: int = None):
         _load_scraped_video(vid, channel)
 
 
+def schedule_update_channels():
+    django_rq.get_scheduler().schedule(
+        datetime.utcnow(),
+        update_channels,
+        id="schedule_update_channels",
+        interval=settings.YT_UPDATE_INTERVAL,
+    )
+
+
 def update_channels():
     """
     Update all channels from their RSS feeds and download new videos.

ucast/tasks/library.py

@@ -0,0 +1,34 @@
+import os
+
+from ucast.models import Video
+from ucast.service import cover, storage
+
+
+def recreate_cover(video: Video):
+    store = storage.Storage()
+    cf = store.get_channel_folder(video.channel.slug)
+
+    thumbnail_file = cf.get_thumbnail(video.slug)
+    cover_file = cf.get_cover(video.slug)
+
+    if not os.path.isfile(cf.file_avatar):
+        print(f"could not find avatar for channel {video.channel_id}")
+        return
+
+    if not os.path.isfile(thumbnail_file):
+        print(f"could not find thumbnail for video {video.id}")
+        return
+
+    cover.create_cover_file(
+        thumbnail_file,
+        cf.file_avatar,
+        video.title,
+        video.channel.name,
+        cover.COVER_STYLE_BLUR,
+        cover_file,
+    )
+
+
+def recreate_covers():
+    for video in Video.objects.all():
+        recreate_cover(video)

ucast/tests/test_youtube.py

@@ -10,7 +10,7 @@ from PIL import Image, ImageChops
 from ucast import tests
 from ucast.service import youtube
 
-VIDEO_ID_SINTEL = "eRsGyueVLvQ"
+VIDEO_ID_THETADEV = "ZPxEr4YdWt8"
 VIDEO_ID_SHORT = "lcQZ6YwQHiw"
 VIDEO_ID_PERSUASION = "DWjFW7Yq1fA"
 
@@ -21,14 +21,14 @@ CHANNEL_URL_BLENDER = "https://www.youtube.com/c/BlenderFoundation"
 
 @pytest.fixture(scope="module")
 def video_info() -> youtube.VideoDetails:
-    return youtube.get_video_details(VIDEO_ID_SINTEL)
+    return youtube.get_video_details(VIDEO_ID_THETADEV)
 
 
 def test_download_thumbnail(video_info):
     tmpdir_o = tempfile.TemporaryDirectory()
     tmpdir = Path(tmpdir_o.name)
     tn_file = tmpdir / "thumbnail"
-    expected_tn_file = tests.DIR_TESTFILES / "thumbnail" / "t2.webp"
+    expected_tn_file = tests.DIR_TESTFILES / "thumbnail" / "t1.webp"
 
     tn_file = youtube.download_thumbnail(video_info, tn_file)
     assert tn_file.suffix == ".webp"
@@ -41,32 +41,26 @@ def test_download_thumbnail(video_info):
 
 
 def test_get_video_info(video_info):
-    assert video_info.id == VIDEO_ID_SINTEL
-    assert video_info.title == "Sintel - Open Movie by Blender Foundation"
-    assert video_info.channel_id == "UCSMOQeBJ2RAnuFungnQOxLg"
+    assert video_info.id == VIDEO_ID_THETADEV
+    assert video_info.title == "ThetaDev @ Embedded World 2019"
+    assert video_info.channel_id == "UCGiJh0NZ52wRhYKYnuZI08Q"
     assert (
         video_info.description
-        == """Help us making Free/Open Movies: https://cloud.blender.org/join
+        == """This february I spent one day at the Embedded World in Nuremberg. They showed tons of interesting electronics stuff, so I had to take some pictures and videos for you to see ;-)
 
-"Sintel" is an independently produced short film, initiated by the Blender Foundation \
-as a means to further improve and validate the free/open source 3D creation suite \
-Blender. With initial funding provided by 1000s of donations via the internet \
-community, it has \
-again proven to be a viable development model for both open 3D technology as for \
-independent animation film.
-This 15 minute film has been realized in the studio of the Amsterdam Blender \
-Institute, by an international team of artists and developers. In addition to \
-that, several crucial technical and creative targets have been realized online, \
-by developers and artists and teams all over the world.
+Sorry for the late upload, I just didn't have time to edit my footage.
 
-www.sintel.org"""
+Embedded World: https://www.embedded-world.de/
+
+My website: https://thdev.org
+Twitter: https://twitter.com/Theta_Dev"""
     )
-    assert video_info.duration == 888
+    assert video_info.duration == 267
     assert not video_info.is_currently_live
     assert not video_info.is_livestream
     assert not video_info.is_short
     assert video_info.published == datetime.datetime(
-        2010, 9, 30, tzinfo=datetime.timezone.utc
+        2019, 6, 2, tzinfo=datetime.timezone.utc
     )
 
 

ucast_project/settings.py

@@ -84,7 +84,7 @@ ALLOWED_HOSTS = []
 # Application definition
 
 INSTALLED_APPS = [
-    "ucast.apps.UcastConfig",
+    "ucast",
     "django.contrib.admin",
     "django.contrib.auth",
     "django.contrib.contenttypes",
@@ -203,13 +203,12 @@ STATICFILES_DIRS = [resources.path("ucast", "static")]
 
 DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
 
-# Delay between YouTube API calls
-YOUTUBE_SCRAPE_DELAY = 1
-
 REDIS_HOST = get_env("REDIS_HOST", "localhost")
 REDIS_PORT = get_env("REDIS_PORT", 6379)
 REDIS_PASSWORD = get_env("REDIS_PASSWORD", "")
 REDIS_DB = get_env("REDIS_DB", 0)
+REDIS_QUEUE_TIMEOUT = get_env("REDIS_QUEUE_TIMEOUT", 600)
+REDIS_QUEUE_RESULT_TTL = 600
 
 RQ_QUEUES = {
     "default": {
@@ -217,8 +216,11 @@ RQ_QUEUES = {
         "PORT": REDIS_PORT,
         "DB": REDIS_DB,
         "PASSWORD": REDIS_PASSWORD,
-        "DEFAULT_TIMEOUT": get_env("REDIS_QUEUE_TIMEOUT", 360),
+        "DEFAULT_TIMEOUT": REDIS_QUEUE_TIMEOUT,
+        "DEFAULT_RESULT_TTL": REDIS_QUEUE_RESULT_TTL,
     }
 }
 
 RQ_SHOW_ADMIN_LINK = True
+
+YT_UPDATE_INTERVAL = get_env("YT_UPDATE_INTERVAL", 900)