Ошибка с PNG (проблема в Watermark) - DatsoGallery

<?php
    /***************************************************\
	**   DatsoGallery - A Joomla! Gallery Component    **
	**   Copyright (C) 2006-2008  by Andrey Datso      **
	**   Version     : 1.6                             **
	**   Homepage    : http://www.datso.fr             **
	**   License     : Copyright, don't distribute     **
    **   Modified by : Aliaksandr Rudik                **
	\***************************************************/

    defined ('_VALID_MOS') or die('Direct Access to this location is not allowed.');
    $pic = "";
    $path = "";
    $id = 0;
    $mid = intval( mosGetParam( $_REQUEST, 'mid', 0 ) );
    $oid = intval( mosGetParam( $_REQUEST, 'oid', 0 ) );
    if ($mid) {
    $pic = "imgfilename";
    $path = $picturedir;
    $id = $mid;
    } else if ($oid) {
    $pic = "imgoriginalname";
    $path = $originaldir;
    $id = $oid;
    }

    if ($id) {
    $database->setQuery("select c.access "
    . " from #__datsogallery_catg as c "
    . " left join #__datsogallery as a on a.catid = c.cid "
    . " where a.id = $id ");
    $c_access = $database->loadResult();

    if ($gid < $c_access) {
    exit;
    }else{
    $database->setQuery("select a.$pic "
    . " from #__datsogallery as a "
    . " where a.id = $id ");

    $pic = $database->loadResult();
    $pic = $path.$pic;
    }

    $img_info = getimagesize($pic);
    if (!$img_info) {
    exit;
    }else{
    $watermark = $gallerydir.'/watermark.png';
    $watermark = imagecreatefrompng($watermark);
    $watermark_width = imagesx($watermark);
    $watermark_height = imagesy($watermark);
    $image = imagecreatetruecolor($watermark_width, $watermark_height);
    $image = imagecreatefromjpeg($pic);
    $size = getimagesize($pic);
    $dest_x = $size[0] - $watermark_width - 5;
    $dest_y = $size[1] - $watermark_height - 5;
    imagecopyresampled($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, $watermark_width, $watermark_height);
    header('content-type: image/jpeg');
    imagejpeg($image, '', $dest_qual=95);
    imagedestroy($image);
    imagedestroy($watermark);
    }
    }
?>