added crop method

README.md

@@ -49,6 +49,7 @@ Add the facade of this package to the `$aliases` array.
 * Image::make - Open a new image resource from image file or create a new empty image
 * Image::canvas - Create a new empty image resource
 * Image::resize - Resize current image based on given width and/or height
+* Image::crop - Crop the current image
 * 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 (-100 = min brightness, 0 = no change, +100 = max brightness)
@@ -99,6 +100,22 @@ $img->reset();
 $img->save('public/bar.jpg', 60);
 ```
 
+#### Crop image
+
+```php
+// create Image from file
+$img = Image::make('public/foo.jpg');
+
+// crop 300x200 pixel cutout at position x:200, y:100
+$img->crop(300, 200, 200, 100);
+
+// crop 300x200 pixel cutout centered on current image
+$img->crop(300, 200);
+
+// save image
+$img->save();
+```
+
 #### Smart resizing
 
 ```php

src/Intervention/Image/Image.php

@@ -315,6 +315,36 @@ class Image
         return $this->resize($width, $height, true);
     }
 
+    /**
+     * Crop the current image
+     *
+     * @param  integer $width
+     * @param  integer $height
+     * @param  integer $pos_x
+     * @param  integer $pos_y
+     *
+     * @return Image
+     */
+    public function crop($width, $height, $pos_x = null, $pos_y = null)
+    {
+        $width = is_numeric($width) ? intval($width) : null;
+        $height = is_numeric($height) ? intval($height) : null;
+        $pos_x = is_numeric($pos_x) ? intval($pos_x) : null;
+        $pos_y = is_numeric($pos_y) ? intval($pos_y) : null;
+
+        if (is_null($pos_x) && is_null($pos_y)) {
+            // center position of width/height rectangle
+            $pos_x = floor(($this->width - intval($width)) / 2);
+            $pos_y = floor(($this->height - intval($height)) / 2);
+        }
+
+        if (is_null($width) || is_null($height)) {
+            throw new Exception('width and height of cutout needs to be defined');
+        }
+
+        return $this->modify(0, 0, $pos_x , $pos_y, $width, $height, $width, $height);
+    }
+
     /**
      * Cut out a detail of the image in given ratio and resize to output size
      *

tests/ImageTest.php

@@ -107,6 +107,25 @@ class ImageTest extends PHPUnit_Framework_Testcase
         $this->assertEquals($img->height, $original_height);
     }
 
+    public function testCropImage()
+    {
+        $img = $this->getTestImage();
+        $img->crop(100, 100);
+        $this->assertInternalType('int', $img->width);
+        $this->assertInternalType('int', $img->height);
+        $this->assertEquals($img->width, 100);
+        $this->assertEquals($img->height, 100);
+        $this->assertEquals('#ffbe46', $img->pickColor(99, 99, 'hex'));
+
+        $img = $this->getTestImage();
+        $img->crop(100, 100, 650, 400);
+        $this->assertInternalType('int', $img->width);
+        $this->assertInternalType('int', $img->height);
+        $this->assertEquals($img->width, 100);
+        $this->assertEquals($img->height, 100);
+        $this->assertEquals('#ffa600', $img->pickColor(99, 99, 'hex'));
+    }
+
     public function testLegacyResize()
     {
         // auto height