added brightness and contrast methods

README.md

@@ -46,6 +46,8 @@ Add the facade of this package to the `$aliases` array.
 * Image::resize - Resize image based on given width and/or height
 * Image::grab - Cut out a detail of the image in given ratio and resize to output size
 * Image::insert - Insert another image on top of the current image
+* Image::brightness - Changes brightness of current image
+* Image::contrast - Changes contrast of current image
 * Image::pixelate - Pixelate current image
 * Image::greyscale - Turn current image into a greyscale version
 * Image::text - Write text in current image

src/Intervention/Image/Image.php

@@ -405,6 +405,30 @@ class Image
         return $this;
     }
 
+    /**
+     * Changes the brightness of the current image
+     * 
+     * @param  int $level [description]
+     * @return Image
+     */
+    public function brightness($level)
+    {
+        imagefilter($this->resource, IMG_FILTER_BRIGHTNESS, $level);
+        return $this;
+    }
+
+    /**
+     * Changes the contrast of the current image
+     * 
+     * @param  int $level
+     * @return Image    
+     */
+    public function contrast($level)
+    {
+        imagefilter($this->resource, IMG_FILTER_CONTRAST, $level);
+        return $this;
+    }
+
     /**
      * Pixelate current image
      * 

tests/ImageTest.php

@@ -294,4 +294,20 @@ class ImageTest extends PHPUnit_Framework_Testcase
 
     }
 
+    public function testBrightnessImage()
+    {
+        $img = $this->getTestImage();
+        $img->brightness(50);
+        $img->brightness(-50);
+        $this->assertInstanceOf('Intervention\Image\Image', $img);
+    }
+
+    public function testContrastImage()
+    {
+        $img = $this->getTestImage();
+        $img->contrast(50);
+        $img->contrast(-50);
+        $this->assertInstanceOf('Intervention\Image\Image', $img);
+    }
+
 }