在图片中写入中文

<?php
header(“Content-type: image/gif”);
$pic=”nv.jpg”;
if (empty($txt)){
$txt=”请输入文字试验”;
}
$str = gb2utf8($txt);
$pich=ImageCreateFromJPEG($pic);
$color=ImageColorAllocate($pich,0,128,192);
ImageTTFText($pich,12,0,10,20,$color,”./simkai.ttf”,$str);
ImageJPEG($pich);
ImageDestroy($pich);

function u2utf8($c)
{
for($i=0;$i<count($c);$i++)
$str=””;
if ($c < 0x80)
$str.=$c;
elseif ($c < 0x800)
{
$str.=(0xC0 | $c>>6);
$str.=(0x80 | $c & 0x3F);
}
elseif ($c < 0x10000)
{
$str.=(0xE0 | $c>>12);
$str.=(0x80 | $c>>6 & 0x3F);
$str.=(0x80 | $c & 0x3F);
}
elseif ($c < 0x200000)
{
$str.=(0xF0 | $c>>18);
$str.=(0x80 | $c>>12 & 0x3F);
$str.=(0x80 | $c>>6 & 0x3F);
$str.=(0x80 | $c & 0x3F);
}
return $str;
}

function gb2utf8($gb)
{
if(!trim($gb))
return $gb;
$filename=”gb2312.txt”;
$tmp=file($filename);
$codetable=array();
while(list($key,$value)=each($tmp))
$codetable[hexdec(substr($value,0,6))]=substr($value,7,6);

$ret=””;
$utf8=””;
while($gb)
{
if (ord(substr($gb,0,1))>127)
{
$thi=substr($gb,0,2);
$gb=substr($gb,2,strlen($gb));
$utf8=u2utf8(hexdec($codetable[hexdec(bin2hex($thi))-0x8080]));
for($i=0;$i<strlen($utf8);$i+=3)
$ret.=chr(substr($utf8,$i,3));
}
else
{
$ret.=substr($gb,0,1);
$gb=substr($gb,1,strlen($gb));
}
}
return $ret;
}
?>