Mine

define("IMAGE_FULL", 0);define("IMAGE_THUMB", 1);define("IMAGE_TINY", 2);$IMAGE_PATHS = array(	IMAGE_FULL => "images/",	IMAGE_THUMB => "images/thumb/",	IMAGE_TINY => "images/tiny/");function imagePath($filename, $pathtype = IMAGE_FULL){	global $IMAGE_PATHS;	if($pathtype < IMAGE_FULL || $pathtype > IMAGE_TINY) $pathtype = IMAGE_FULL;	$fullPath = $IMAGE_PATHS[IMAGE_FULL].$filename;	if(!file_exists($fullPath)){		return $fullPath; // whelp, you're getting a broken image.	}	if($pathtype == IMAGE_THUMB){		// 133x100		$destPath = $IMAGE_PATHS[IMAGE_THUMB].$filename;		if(!file_exists($destPath)){			makeThumb($fullPath, $destPath, 133, 100);		}		return $destPath;	} elseif($pathtype == IMAGE_TINY) {		// 50x50		$destPath = $IMAGE_PATHS[IMAGE_TINY].$filename;		if(!file_exists($destPath)){			makeThumb($fullPath, $destPath, 50, 50);		}		return $destPath;	} else { //IMAGE_FULL		return $IMAGE_PATHS[IMAGE_FULL].$filename;		}}function makeThumb($source, $dest, $width, $height){	list($srcWidth, $srcHeight, $typeConst) = getimagesize($source);	$srcAspect = $srcWidth/$srcHeight;	$destAspect = $width/$height;	$scale = 1.0;	$gdSrc;	$gdDest = imagecreatetruecolor($width, $height);		if($srcAspect > $destAspect){ // fit to height		$scale = $height / $srcHeight;	} else { // fit to width		$scale = $width / $srcWidth;	}		$finalWidth = $scale * $srcWidth;	$finalHeight = $scale * $srcHeight;	$finalX = ($width - $finalWidth)/2;	$finalY = ($height - $finalHeight)/2;		switch($typeConst){		case IMAGETYPE_GIF:			$gdSrc = imagecreatefromgif($source);		break;		case IMAGETYPE_JPEG:			$gdSrc = imagecreatefromjpeg($source);		break;		case IMAGETYPE_PNG:			$gdSrc = imagecreatefrompng($source);		break;		default:			return; // what the hell did you upload? a bitmap? you don't deserve a thumbnail.		break;	}		// Do the resize and resample	imagecopyresampled($gdDest, $gdSrc, $finalX, $finalY, 0, 0, $finalWidth, $finalHeight, $srcWidth, $srcHeight);		switch($typeConst){		case IMAGETYPE_GIF:			imagegif($gdDest, $dest);		break;		case IMAGETYPE_JPEG:			imagejpeg($gdDest, $dest);		break;		case IMAGETYPE_PNG:			imagepng($gdDest, $dest);		break;	}}