【PHP】Transparent watermark generation

/*
 * Created on 2010-10-27
 * BY QQ542900563
 * Copyrights Reserved 2000-2020
 * This example demonstrates how to generate image watermarks
 */
//Load separately Two pictures
$im=imagecreatefromjpeg("liu.jpg");
$img2=imagecreatefrompng("m.png");

//Get their respective length and width, calculate the position
$im_WH=getimagesize("liu. jpg");
$im_W=$im_WH[0];
$im_H=$im_WH[1];

$img2_WH=getimagesize("m.png");
$img2_W=$img2_WH[0];
$ img2_H=$img2_WH[1];

//Define the storage location
$NewX=$im_W-$img2_W;
$NewY=$im_H-$img2_H;

//Fill
imagecopy($im,$img2, $NewX,$NewY,0,0,$img2_W,$img2_H);

header("Content-type:image/jpeg");
imagejpeg($im);

?>