php imagecreate图片生成代码

f(isset($gd) && $gd==1&& $txt)
{
 header ("Content-type: image/png");
 $txt = urldecode(phpcms_auth($txt, 'DECODE',AUTH_KEY));
 $imageX = strlen($txt)*9;
 $im = @imagecreate ($imageX, 16) or die ("CannotInitialize new GD image stream");
 $bgColor =ImageColorAllocate($im,255,255,255);
 $white=imagecolorallocate($im,234,185,95);
 $font_color=imagecolorallocate($im,0x00,0x00,0x00);
 
 $fontfile =PHPCMS_ROOT."include/fonts/simfang.ttf";
 if(file_exists($fontfile)&&!preg_match('/([a-z0-9@.])/',$txt))
 {
  $txt =iconv("GB2312","UTF-8",$txt);
  ImageTTFText($im, 10, 0, 0, 12,$font_color, $fontfile, $txt);
 }
 else
 {
  $fonttype =intval($fonttype);
  imagestring ($im, $fonttype, 0,0,$txt, $font_color);
 }
 imagepng ($im);
 imagedestroy ($im);
}