/**
* Apply the transformation to the image and returns the image thumbnail
*/
protected function transform(sfImage $image)
{
// Work out where we need to draw to
$offset = $this->getThickness() / 2;
$mod = $this->getThickness() % 2;
$x2 = $image->getWidth() - $offset - ($mod === 0 ? 1 : 0);
$y2 = $image->getHeight() - $offset - ($mod === 0 ? 1 : 0);
$image->rectangle($offset, $offset, $x2, $y2, $this->getThickness(), $this->getColor());
return $image;
}
