Alpha on thumbs [Flatpress]

--- plugin.thumb_old.php    2011-08-25 13:22:00.000000000 +0200
+++ plugin.thumb.php    2011-08-25 13:24:29.000000000 +0200
@@ -84,7 +84,7 @@

    switch($infos[2]) {
        case 1: $image = imagecreatefromgif($fpath); break;
-       case 2: $image = imagecreatefromjpeg ($fpath); break;
+       case 2: $image = imagecreatefromjpeg($fpath); break;
        case 3: $image = imagecreatefrompng($fpath);
    }

@@ -93,12 +93,32 @@

    // create empty scaled and copy(resized) the picture

-
-
    $scaled = imagecreatetruecolor($new_width, $new_height);
+
+   /*
+    * If gif or png preserve the alpha channel
+    *
+    * Added by Piero VDFN
+    * Kudos to http://www.php.net/manual/en/function.imagecopyresampled.php#104028
+    */
+   if($infos[2]==1 || $infos[2]==3) {
+       imagecolortransparent($scaled, imagecolorallocatealpha($scaled, 0, 0, 0, 127));
+       imagealphablending($scaled, false);
+       imagesavealpha($scaled, true);
+       $output=$infos[2]==3 ? 'png' : 'gif';
+   } else {
+       $output='jpg';
+   }
+
    imagecopyresampled($scaled, $image, 0, 0, 0, 0, $new_width, $new_height, $infos[0], $infos[1]);

-   imagejpeg($scaled, $thumbpath);
+   if($output=='png') {
+       imagepng($scaled, $thumbpath);
+   } elseif($output=='gif') {
+       imagegif($scaled, $thumbpath);
+   } else {
+       imagejpeg($scaled, $thumbpath);
+   }
    @chmod($thumbpath, FILE_PERMISSIONS);

    return array($thumbpath, $new_width, $new_height);