function pad(\Imagine\Gd\Imagine $img, \Imagine\Image\Box $size, $fcolor = '#000', $ftransparency = 100)
{
$tsize = $img->getSize();
$x = $y = 0;
if ($size->getWidth() > $tsize->getWidth()) {
$x = round(($size->getWidth() - $tsize->getWidth()) / 2);
} elseif ($size->getHeight() > $tsize->getHeight()) {
$y = round(($size->getHeight() - $tsize->getHeight()) / 2);
}
$pasteto = new \Imagine\Image\Point($x, $y);
$imagine = new \Imagine\Gd\Imagine();
$color = new \Imagine\Image\Color($fcolor, $ftransparency);
$image = $imagine->create($size, $color);
$image->paste($img, $pasteto);
return $image;
}