Merging two images and saving the result in database

Hello all,

I am trying to merge two images using PHP and then to save the result in the database (as BLOB). However, the script always saves a blob of 1B size.

Here's the code:

if ($_FILES['userfile']['error'] == 0 && $_FILES['userfile']['size'] > 0) {
$uploaddir = "images/";
$fileName = $_FILES['userfile']['name'];
$tmpName = $_FILES['userfile']['tmp_name'];
$fileSize = $_FILES['userfile']['size'];
$fileType = $_FILES['userfile']['type'];

define( 'WATERMARK_OVERLAY_IMAGE', base_url().'img/site_images/profile_pic_overlay.png' );


list( $source_width, $source_height, $source_type ) = getimagesize( $tmpName );

if ($source_type) {
switch ( $source_type )
{
case IMAGETYPE_GIF:
$source_gd_image = imagecreatefromgif( $tmpName );
break;
case IMAGETYPE_JPEG:
$source_gd_image = imagecreatefromjpeg( $tmpName );
break;
case IMAGETYPE_PNG:
$source_gd_image = imagecreatefrompng( $tmpName );
break;
default:
return false;
}

$overlay_gd_image = imagecreatefrompng( WATERMARK_OVERLAY_IMAGE );
$overlay_width = imagesx( $overlay_gd_image );
$overlay_height = imagesy( $overlay_gd_image );


$temp = imagecopymerge(
$source_gd_image,
$overlay_gd_image,
0,
0,
0,
0,
$overlay_width,
$overlay_height,
75
);

$content = imagejpeg( $source_gd_image );
$fileType = "image/jpeg";

imagedestroy( $source_gd_image );
imagedestroy( $overlay_gd_image );
}
}


and then need to save $content in a database table (which works when I don't try to merge the images.

Any ideas?

Many thanks.

Shmoyko