public static function saveImage( $fileName, $resource, $type = IMAGETYPE_PNG, $quality = 100 )
	{
		switch( $type )
		{
			case IMAGETYPE_PNG:
				ImagePNG( $resource, $fileName );
				break;
			case IMAGETYPE_JPEG:
				ImageJPEG( $resource, $fileName, $quality );
				break;
			case IMAGETYPE_GIF:
				ImageGIF( $resource, $fileName );
				break;
			default:
				throw new InvalidArgumentException( 'Invalid Image Type' );
		}
	}