I want to place the watermark at the bottom of the original image and resize the watermark so it fits in the original image

here is the code

<?php
require("inc/core.php");
$row = $db->query("SELECT type,original FROM photos WHERE id =".$_GET['i']);
$row = $row->fetch_assoc();
$loc = $row['original'];



if($type == "image/jpeg") {
echo $row['original'];
//header('content-type: image/jpeg');

$watermark = imagecreatefrompng('images/watermark.png');
$watermark_width = imagesx($watermark);
$watermark_height = imagesy($watermark);
$image = imagecreatetruecolor($watermark_width, $watermark_height);
$image = imagecreatefromjpeg($loc);
$size = getimagesize($loc);
$dest_x = $size[0] - $watermark_width - 5;
$dest_y = $size[1] - $watermark_height - 5;
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 100);
//imagejpeg($image);
imagedestroy($image);
imagedestroy($watermark);
} elseif($type == "image/gif") {
} elseif($type == "image/png") {
}
?>