Added new plugin "Optimize Images"

optimize_images/Readme.md

@@ -0,0 +1,26 @@
+Optimize Images Plugin For Pelican
+==================================
+
+This plugin applies lossless compression on JPEG and PNG images, with no
+effect on image quality. It uses [jpegtran][1] and [OptiPNG][2]. It assumes
+that both of these tools are installed on system path.
+
+[1]: http://jpegclub.org/jpegtran/              "jpegtran"
+[2]: http://optipng.sourceforge.net/            "OptiPNG"
+
+
+Installation
+------------
+
+To enable, ensure that `optimize_images.py` is put somewhere that is accessible.
+Then use as follows by adding the following to your settings.py:
+
+    PLUGIN_PATH = 'path/to/pelican-plugins'
+    PLUGINS = ["optimize_images"]
+
+`PLUGIN_PATH` can be a path relative to your settings file or an absolute path.
+
+Usage
+-----
+The plugin will activate and optimize images upon `finalized` signal of
+pelican.

optimize_images/optimize_images.py

@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+
+"""
+Optimized images (jpg and png)
+Assumes that jpegtran and optipng are isntalled on path.
+http://jpegclub.org/jpegtran/
+http://optipng.sourceforge.net/
+Copyright (c) 2012 Irfan Ahmad (http://i.com.pk)
+"""
+
+import logging
+import os
+from subprocess import call
+
+from pelican import signals
+
+logger = logging.getLogger(__name__)
+
+# A list of file types with their respective commands
+COMMANDS = [
+    ('.jpg', 'jpegtran -copy none -optimize "{filename}" "{filename}"'),
+    ('.png', 'optipng "{filename}"'),
+]
+
+def optimize_images(pelican):
+    """
+    Optimized jpg and png images
+
+    :param pelican: The Pelican instance
+    """
+    for dirpath, _, filenames in os.walk(pelican.settings['OUTPUT_PATH']):
+        for name in filenames:
+            optimize(dirpath, name)
+
+def optimize(dirpath, filename):
+    """
+    Check if the name is a type of file that should be optimized.
+    And optimizes it if required.
+
+    :param dirpath: Path of the file to be optimzed
+    :param name: A file name to be optimized
+    """
+    for extension, command in COMMANDS:
+        if filename.endswith(extension):
+            filepath = os.path.join(dirpath, filename)
+            command = command.format(filename=filepath)
+            call(command, shell=True)
+
+
+def register():
+    signals.finalized.connect(optimize_images)