Merge pull request #148 from abdul/watermark_plugin

Watermark Plugin

AUTHORS

@@ -8,3 +8,4 @@ alphabetical order):
 - Matthias Vogelgesang
 - Vikram Shirgur
 - Yuce Tekol
+- Abdul Qabiz

docs/plugins.rst

@@ -103,3 +103,8 @@ Upload to S3 plugin
 ===================
 
 .. automodule:: sigal.plugins.upload_s3
+
+Watermark plugin
+===================
+
+.. automodule:: sigal.plugins.watermark

sigal/plugins/watermark.py

@@ -0,0 +1,98 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2005 - Shane Hathaway (http://code.activestate.com/recipes/362879-watermark-with-pil/)
+# Copyright (c) 2015 - Abdul Qabiz
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+"""Plugin which adds a watermark to the image.
+
+Settings:
+
+- ``watermark``: path to the watermark image.
+- ``watermark_position``: the watermark position either 'scale' or 'tile' or
+                          a 2-tuple giving the upper left corner, or
+                          a 4-tuple defining the left, upper, right, and lower pixel coordinate, or
+                          `None` (same as (0, 0)).
+                          If a 4-tuple is given, the size of the pasted image must match the size of the region.
+- ``watermark_opacity``: the watermark opacity (0.0 to 1.0).
+
+"""
+
+
+import logging
+from PIL import ImageDraw, Image, ImageEnhance
+from sigal import signals
+
+logger = logging.getLogger(__name__)
+
+
+def reduce_opacity(im, opacity):
+    """Returns an image with reduced opacity."""
+    assert opacity >= 0 and opacity <= 1
+    if im.mode != 'RGBA':
+        im = im.convert('RGBA')
+    else:
+        im = im.copy()
+    alpha = im.split()[3]
+    alpha = ImageEnhance.Brightness(alpha).enhance(opacity)
+    im.putalpha(alpha)
+    return im
+
+
+def watermark(im, mark, position, opacity=1):
+    """Adds a watermark to an image."""
+    if opacity < 1:
+        mark = reduce_opacity(mark, opacity)
+    if im.mode != 'RGBA':
+        im = im.convert('RGBA')
+    # create a transparent layer the size of the image and draw the
+    # watermark in that layer.
+    layer = Image.new('RGBA', im.size, (0, 0, 0, 0))
+    if position == 'tile':
+        for y in range(0, im.size[1], mark.size[1]):
+            for x in range(0, im.size[0], mark.size[0]):
+                layer.paste(mark, (x, y))
+    elif position == 'scale':
+        # scale, but preserve the aspect ratio
+        ratio = min(
+            float(im.size[0]) / mark.size[0], float(im.size[1]) / mark.size[1])
+        w = int(mark.size[0] * ratio)
+        h = int(mark.size[1] * ratio)
+        mark = mark.resize((w, h))
+        layer.paste(mark, ((im.size[0] - w) / 2, (im.size[1] - h) / 2))
+    else:
+        layer.paste(mark, position)
+    # composite the watermark with the layer
+    return Image.composite(layer, im, layer)
+
+
+def add_watermark(img, settings=None):
+    logger.debug('Adding watermark to %r', img)
+    mark = Image.open(settings['watermark'])
+    position = settings.get('watermark_position', 'scale')
+    opacity = settings.get("watermark_opacity", 1)
+    return watermark(img, mark, position, opacity)
+
+
+def register(settings):
+    if settings.get('watermark'):
+        signals.img_resized.connect(add_watermark)
+    else:
+        logger.warning('Watermark image is not set')

sigal/settings.py

@@ -66,6 +66,7 @@ _DEFAULT_CONFIG = {
     'title': '',
     'use_orig': False,
     'video_size': (480, 360),
+    'watermark': '',
     'webm_options': ['-crf', '10', '-b:v', '1.6M',
                      '-qmin', '4', '-qmax', '63'],
     'write_html': True,
@@ -124,7 +125,7 @@ def read_settings(filename=None):
                         if k not in ['__builtins__'])
 
         # Make the paths relative to the settings file
-        paths = ['source', 'destination']
+        paths = ['source', 'destination', 'watermark']
 
         if os.path.isdir(join(settings_path, settings['theme'])):
             paths.append('theme')

tests/sample/sigal.conf.py

@@ -10,10 +10,12 @@ keep_orig = True
 links = [('Example link', 'http://example.org'),
          ('Another link', 'http://example.org')]
 
-plugins = ['sigal.plugins.adjust', 'sigal.plugins.copyright']
+plugins = ['sigal.plugins.adjust', 'sigal.plugins.copyright', 'sigal.plugins.watermark']
 copyright = u"© An example copyright message"
 adjust_options = {'color': 0.0, 'brightness': 1.0,
                   'contrast': 1.0, 'sharpness': 0.0}
-
+watermark = "watermark.png"
+watermark_position = "tile"
+watermark_opacity = 0.3
 # theme = 'galleria'
 # thumb_size = (280, 210)