图片上写中文

$text=iconv('gb2312','UTF-8','我爱中国');
//构造图像
$font='tianwu.ttf';
$pic=imagecreatefromjpeg('mm.jpg');
$color = imagecolorallocate($pic, 0,255,0);
imagettftext($pic,30,mt_rand(-8,8),100,100,$color,$font,$text);
//imagerectangle($pic, 0, 0, $x_size - 1, $y_size - 1,$black);绘矩形
Imagepng($pic);
ImageDestroy($pic);
?>