PHP Image Filter GD: Apply image effect filters to remote images

App:       PHP Image Filter GD
Version:   1.0.1
Author:    MT Jordan <mtjo62@gmail.com>
Copyright: 2014
License:   zlib/libpng License

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Image Image Filter GD: Image class to apply effects filters to remote images

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Image Filter GD is PHP class that can apply image effects filters to remotely linked images. The class can be used with CMS's, blogs or other forum applications as a base for BBCode style tags or it can be applied using Javascript. 

brighten: Lightens a darker image.
brush: Adds a slight dabbed, brushed effect to an image.
darken: Darkens an overly bright image.
edgedetect: Highlights borders between colors on an image. Similar to emboss.
emboss: Adds a stamped metal effect to an image.
flip: Flips an image vertically.
grayscale: Converts color image to black & white.
larger: Increase an image dimension by 2x.
mirror: Produces a mirrored reflection of an image.
negative: Produces a photo negative of an image.
pixelate: Pixilates an image.
sephia: Adds an aged photo effect to an image.
sharpen: Sharpens an blurred image.
sketch: Adds a sketched, comic book effect to an image.
smaller: Reduces an image dimension size by half.
smooth: Slightly blurs an overly sharpened image.

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Image Filter GD Features:

    * Effects filters are non destructive to original image.

Image Filter GD Restrictions:

    * Only supports GIF, PNG and JPG/JPEG images.
    * Only the first frame of animated GIFs are processed.
  
Image Filter GD Requirements:

    * PHP 5.4+
    * Enabled GD extension
    * Enabled fopen wrappers or cURL extension

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Installation:

1. Upload image_filter.php and error.png to a readable directory. 
2. Download the PHP Image cURL dependency package image_info.php if using the cURL extension and upload to the same directory as step 1.

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For a standalone img tag

Usage: 

<img src="http://mysite.com/path/to/image_filter.php?filename_gd=http://mysite.com/path/to/image.png&filter_gd=sharpen" alt="" />

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For a Smarty Plugin

Download function.img_filter.php and upload to the plugins directory of your Smarty installation.
Edit the $img_filter_URL variable to the absolute path to image_filter.php.

Add the following to your template.

{img_filter src='http://mysite.com/path/to/image.png' filter='smaller'}

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For a BBCode style tag

Usage: 

[img_filter=sharpen]http://mysite.com/path/to/image.png[/img_filter]

Use the following as the Regular Expression 

\[img_filter=(.*?)\](.*?)\[/img_filter\]

Use the following as the Replacement.

<img src="http://mysite.com/path/to/image_filter.php?filename_gd=$2&filter_gd=$1" alt="$2" />

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Using the image_filter.js file and the class name filter and the alt attribute as the effect filter

Note: See filter.html for working example

Download the image_filter.js file and upload to a readable directory. Open image_filter.js and edit the url variable
to: http://mysite.com/path/to/image_filter.php

Add the following script include to the footer of your page or template:

<script type="text/javascript" src="http://mysite.com/path/to/image_filter.js"></script>

Usage:

<img src="http://mysite.com/path/to/image.png" class="filter_gd" alt="sharpen" />