/**
  * Apply the transformation to the image and returns the image thumbnail
  */
 protected function transform(sfImage $image)
 {
     $resource_w = $image->getWidth();
     $resource_h = $image->getHeight();
     $scale_w = $this->getWidth() / $resource_w;
     $scale_h = $this->getHeight() / $resource_h;
     switch ($this->getMethod()) {
         case 'deflate':
         case 'inflate':
             return $image->resize($this->getWidth(), $this->getHeight());
         case 'left':
             $image->scale(max($scale_w, $scale_h));
             return $image->crop(0, (int) round(($image->getHeight() - $this->getHeight()) / 2), $this->getWidth(), $this->getHeight());
         case 'right':
             $image->scale(max($scale_w, $scale_h));
             return $image->crop($image->getWidth() - $this->getWidth(), (int) round(($image->getHeight() - $this->getHeight()) / 2), $this->getWidth(), $this->getHeight());
         case 'top':
             $image->scale(max($scale_w, $scale_h));
             return $image->crop((int) round(($image->getWidth() - $this->getWidth()) / 2), 0, $this->getWidth(), $this->getHeight());
         case 'bottom':
             $image->scale(max($scale_w, $scale_h));
             return $image->crop((int) round(($image->getWidth() - $this->getWidth()) / 2), $image->getHeight() - $this->getHeight(), $this->getWidth(), $this->getHeight());
         case 'center':
             $image->scale(max($scale_w, $scale_h));
             $left = (int) round(($image->getWidth() - $this->getWidth()) / 2);
             $top = (int) round(($image->getHeight() - $this->getHeight()) / 2);
             return $image->crop($left, $top, $this->getWidth(), $this->getHeight());
         case 'scale':
             return $image->scale(min($scale_w, $scale_h));
         case 'fit':
         default:
             $img = clone $image;
             $image->create($this->getWidth(), $this->getHeight());
             // Set a background color if specified
             if (!is_null($this->getBackground()) && $this->getBackground() != '') {
                 $image->fill(0, 0, $this->getBackground());
             }
             $img->scale(min($this->getWidth() / $img->getWidth(), $this->getHeight() / $img->getHeight()));
             $image->overlay($img, 'center');
             return $image;
     }
 }