function create_png()
{
// PNG image data, 1 x 1, 1-bit colormap, non-interlaced
ob_start();
imagepng(imagecreatefromstring(base64_decode('R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7')));
$raw_image = ob_get_contents();
ob_end_clean();
return $raw_image;
}