public static function run($dataDir = null)
 {
     # Load an existing image (of type bmp) in an instance of Image class
     $image = new Image();
     $image = $image->load($dataDir . "demo.djvu");
     # Create an instance of BmpOptions
     $export_options = new BmpOptions();
     # Set BitsPerPixel for resultant images
     $export_options->setBitsPerPixel(32);
     # Create an instance of IntRange and initialize it with range of pages to be exported
     $range = [0, 1];
     #Export first 2 pages
     $i = 0;
     while ($i < 2) {
         # Save each page in separate file, as BMP do not support layering
         $export_options->setMultiPageOptions(new DjvuMultiPageOptions($i));
         $image->save($dataDir . "djvupages#{i}.bmp", $export_options);
         $i += 1;
     }
     # Display Status.
     print "Converted range of DjVu pages to separate images successfully!" . PHP_EOL;
 }