gistfile1.php

Configure::write('Assets.ImageSize.suitcaseImage191×175', array(
	'name' => 'suitcaseImage191×175',
	'callback' => function($Image) {
		$Image->applyFilter('resize', array('width' => 0, 'height' => 175));
		if($Image->getImageWidth() > 191) {
			$Image->applyFilter('resize', array('width' => 191, 'height' => 0));
		}
		$Image->applyFilter('canvas', array('width' => $Image->getImageWidth(), 'height' => $Image->getImageHeight()));
	}
));