Add Upscale filter

Imagine/Filter/Loader/UpscaleFilterLoader.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Liip\ImagineBundle\Imagine\Filter\Loader;
+
+use Imagine\Filter\Basic\Resize;
+use Imagine\Image\ImageInterface;
+use Imagine\Image\Box;
+use Liip\ImagineBundle\Imagine\Filter\Loader\LoaderInterface;
+
+/**
+ * Upscale filter
+ *
+ * @author Maxime Colin <[email protected]>
+ */
+class UpscaleFilterLoader implements LoaderInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function load(ImageInterface $image, array $options = array())
+    {
+        if (!isset($options['min'])) {
+            throw new InvalidArgumentException('Missing min option.');
+        }
+
+        list($width, $height) = $options['min'];
+
+        $size = $image->getSize();
+        $origWidth = $size->getWidth();
+        $origHeight = $size->getHeight();
+
+        if ($origWidth < $width || $origHeight < $height) {
+
+            $widthRatio = $width / $origWidth ;
+            $heightRatio = $height / $origHeight;
+
+            $ratio = $widthRatio > $heightRatio ? $widthRatio : $heightRatio;
+
+            $filter = new Resize(new Box($origWidth * $ratio, $origHeight * $ratio));
+
+            return $filter->apply($image);
+        }
+
+        return $image;
+    }
+}

Resources/config/imagine.xml

@@ -41,6 +41,7 @@
         <parameter key="liip_imagine.filter.loader.watermark.class">Liip\ImagineBundle\Imagine\Filter\Loader\WatermarkFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.strip.class">Liip\ImagineBundle\Imagine\Filter\Loader\StripFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.background.class">Liip\ImagineBundle\Imagine\Filter\Loader\BackgroundFilterLoader</parameter>
+        <parameter key="liip_imagine.filter.loader.upscale.class">Liip\ImagineBundle\Imagine\Filter\Loader\UpscaleFilterLoader</parameter>
 
         <!-- Data loaders' classes -->
 
@@ -160,6 +161,10 @@
             <tag name="liip_imagine.filter.loader" loader="strip" />
         </service>
 
+        <service id="liip_imagine.filter.loader.upscale" class="%liip_imagine.filter.loader.upscale.class%">
+            <tag name="liip_imagine.filter.loader" loader="upscale" />
+        </service>
+
         <!-- Data loaders -->
 
         <service id="liip_imagine.data.loader.filesystem" class="%liip_imagine.data.loader.filesystem.class%">

Resources/doc/filters.md

@@ -55,6 +55,19 @@ liip_imagine:
                 relative_resize: { scale: 2.5 }   # Transforms 50x40 to 125x100
 ```
 
+### The `upscale` filter
+
+The upscale filter, as the name implies, performs a upscale transformation
+on your image. Configuration looks like this:
+
+``` yaml
+liip_imagine:
+    filter_sets:
+        my_thumb:
+            filters:
+                upscale: { min: [800, 600] }
+```
+
 ### The `crop` filter
 
 The crop filter, as the name implies, performs a crop transformation