Simple watermark

<?phpfunction watermark($image_name){	$image			= new Imagick($image_name); 	$watermark		= new Imagick('slurp-watermark.png'); 	$image_width 		= $image->getImageWidth();	$image_height 		= $image->getImageHeight();	$watermark_width 	= $watermark->getImageWidth();	$watermark_height 	= $watermark->getImageHeight();	if ($image_width < $watermark_width || $image_height < $watermark_height) {		return false;	}	$target_x	= $image_width - $watermark_width;	$target_y	= $image_height	- $watermark_height;	$image->compositeImage( $watermark, Imagick::COMPOSITE_OVER, $target_x, $target_y);	$image->writeImage($image_name); 	return true;}watermark('01.png');?>