Hi, I use this function to resize images but i end up with ugly creepy image with a black background if it's a transparent GIF or PNG with alpha, however it works perfectly for jpg and normal png.

function cropImage($nw, $nh, $source, $stype, $dest) {
     $size = getimagesize($source);
     $w = $size[0];
      $h = $size[1];

      switch($stype) {
          case 'gif':
          $simg = imagecreatefromgif($source);
          break;
          case 'jpg':
          $simg = imagecreatefromjpeg($source);
          break;
          case 'png':
          $simg = imagecreatefrompng($source);
          break;
      }


     $dimg = imagecreatetruecolor($nw, $nh);

     switch ($stype)
    {
         case "png":

     imagealphablending( $dimg, false );
     imagesavealpha( $dimg, true );
     $transparent = imagecolorallocatealpha($dimg, 255, 255, 255, 127);
     imagefilledrectangle($dimg, 0,  0, $nw, $nh,  $transparent);

    break;
case "gif":
    // integer representation of the color black (rgb: 0,0,0)
    $background = imagecolorallocate($simg, 0, 0, 0);
    // removing the black from the placeholder
    imagecolortransparent($simg, $background);

    break;
     }



      $wm = $w/$nw;
      $hm = $h/$nh;
      $h_height = $nh/2;
      $w_height = $nw/2;

      if($w> $h) {
          $adjusted_width = $w / $hm;
          $half_width = $adjusted_width / 2;
          $int_width = $half_width - $w_height;
          imagecopyresampled($dimg,$simg,-$int_width,0,0,0,$adjusted_width,$nh,$w,$h);
      } elseif(($w <$h) || ($w == $h)) {
          $adjusted_height = $h / $wm;
          $half_height = $adjusted_height / 2;
          $int_height = $half_height - $h_height;

     imagecopyresampled($dimg,$simg,0,-$int_height,0,0,$nw,$adjusted_height,$w,$h);
      } else {
          imagecopyresampled($dimg,$simg,0,0,0,0,$nw,$nh,$w,$h);
      }

      imagejpeg($dimg,$dest,100);
     }

I use php 5.3.2 and the GD library bundled (2.0.34 compatible)

Thanks