How does the Image Class Work?

[Jaxel]

So I want to take an image... which is 4:3... resize it, and then crop it to 16:9. I know how to do this using GD2, but sadly it doesnt work with ImageMagick. So now I'm trying to use the existing image classes in VB to handle it... but I can't get them working either...

require_once(DIR . '/includes/class_image.php');
$image =& vB_Image::fetch_library();
$image->fetch_thumbnail($filename, $location, $newWidth, $newHeight, $quality);

Doesnt seem to do anything...

--------------- Added [DATE]1273196508[/DATE] at [TIME]1273196508[/TIME] ---------------

This is what I am using now...

if ($vbulletin->options['imagetype'] == 'GD')
{
	$newImage = imagecreatetruecolor(160, 90);
	$oldImage = imagecreatefromjpeg($target);
	imagecopyresampled($newImage, $oldImage, 0, 0, 0, $offHeight, $newWidth, $newHeight, $oldWidth, $oldHeight);
	unlink($target);
	imagejpeg($newImage, $target, $quality);
}

/*
if ($vbulletin->options['imagetype'] == 'Magick')
{
	$thumb = new Imagick($target);
	$thumb->cropThumbnailImage($newWidth,$newHeight);
	$thumb->writeImage($target);
	$thumb->destroy();
}
*/

The second set is commented out, because I can't get it working... Either I need to figure out how to do this with the built in image classes... or I need to figure out how to do this with the imagick class... I can't figure out either.