thumbs jpeg, gif, png

[seokey]

Allora riepilogo:

così riesco a caricare tutte le jpeg anche effettuando i controlli str_replace

<?php
function createThumbs( $pathToImages, $pathToThumbs, $thumbWidth ) 
{
//$estensioni = array('jpg','jpeg','gif','GIF','JPG','JPEG');
  // open the directory
  $dir = opendir( $pathToImages );

  // loop through it, looking for any/all JPG files:
  while (false !== ($fname = readdir( $dir ))) {
    // parse path for the extension
    $info = pathinfo($pathToImages . $fname);
    $fname = str_replace(" ", "", $fname);
    $fname = str_replace("%20", "", $fname);
    
    // continue only if this is a JPEG image
    if ( strtolower($info['extension']) == 'jpg' || 'GIF' || 'gif' || 'JPEG') 
    {
     // echo "Ho creato miniatura per immagine: {$fname} 
";

      // load image and get image size
      $img = @imagecreatefromjpeg( "{$pathToImages}{$fname}" );
      $width = @imagesx( $img );
      $height = @imagesy( $img );

      // calculate thumbnail size
      $new_width = $thumbWidth;
      $new_height = @floor( $height * ( $thumbWidth / $width ) );

      // create a new temporary image
      $tmp_img = @imagecreatetruecolor( $new_width, $new_height );

      // copy and resize old image into new image 
      @imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

      // save thumbnail into a file
      @imagejpeg( $tmp_img, "{$pathToThumbs}{$fname}" );

    }
  }
  // close the directory
  closedir( $dir );
}
createThumbs("img/","thumbs/",100);
?>

Come posso replicare il tutto per poter effettuare thumb di immagini gif e png?