这个是输出4个验证码的例子，对于汉字，需要font文件和imagettftext函数，用到的时候大家再网上搜索吧。

实例22图片验证的核心代码

代码如下:

<?php

//header("content-type:image/png");

$num='1234';

$imagewidth=60;

$imageheight=18;

$numimage=imagecreate($imagewidth,$imageheight);

imagecolorallocate($numimage,240,240,240);

for($i=0;$i<strlen($num);$i++){

$x=mt_rand(1,8)+$imagewidth*$i/4;

$y=mt_rand(1,$imageheight/4);

$color=imagecolorallocate($numimage,mt_rand(0,150),mt_rand(0,150),mt_rand(0,150));

imagestring($numimage,5,$x,$y,$num[$i],$color);

}

for($i=0;$i<200;$i++){

$randcolor=imagecolorallocate($numimage,rand(200,255),rand(200,255),rand(200,255));

imagesetpixel($numimage,rand()%70,rand()%20,$randcolor);

}

imagepng($numimage);

imagedestroy($numimage);

?>

这个是输出4个验证码的例子，对于汉字，需要font文件和imagettftext函数，用到的时候大家再网上搜索吧。你要产生随机数，那有mt_rand函数；你还要用到session保存这个随机数；如果需要转成utf-8，需要iconv函数。

实例23缩略图

代码如下:

<?php

classSimpleImage{

var$image;

var$image_type;

functionload($filename){

$image_info=getimagesize($filename);

$this->image_type=$image_info[2];

if($this->image_type==IMAGETYPE_JPEG){

$this->image=imagecreatefromjpeg($filename);

}elseif($this->image_type==IMAGETYPE_GIF){

$this->image=imagecreatefromgif($filename);

}elseif($this->image_type==IMAGETYPE_PNG){

$this->image=imagecreatefrompng($filename);

}

}

functionsave($filename,$image_type=IMAGETYPE_JPEG,$compression=75,$permissions=null){

if($image_type==IMAGETYPE_JPEG){

imagejpeg($this->image,$filename,$compression);

}elseif($image_type==IMAGETYPE_GIF){

imagegif($this->image,$filename);

}elseif($image_type==IMAGETYPE_PNG){

imagepng($this->image,$filename);

}

if($permissions!=null){

chmod($filename,$permissions);

}

}

functionoutput($image_type=IMAGETYPE_JPEG){

if($image_type==IMAGETYPE_JPEG){

imagejpeg($this->image);

}elseif($image_type==IMAGETYPE_GIF){

imagegif($this->image);

}elseif($image_type==IMAGETYPE_PNG){

imagepng($this->image);

}

}

functiongetWidth(){

returnimagesx($this->image);

}

functiongetHeight(){

returnimagesy($this->image);

}

functionresizeToHeight($height){

$ratio=$height/$this->getHeight();

$width=$this->getWidth()*$ratio;

$this->resize($width,$height);

}

functionresizeToWidth($width){

$ratio=$width/$this->getWidth();

$height=$this->getheight()*$ratio;

$this->resize($width,$height);

}

functionscale($scale){

$width=$this->getWidth()*$scale/100;

$height=$this->getheight()*$scale/100;

$this->resize($width,$height);

}

functionresize($width,$height){

$new_image=imagecreatetruecolor($width,$height);

imagecopyresampled($new_image,$this->image,0,0,0,0,$width,$height,$this->getWidth(),$this->getHeight());

$this->image=$new_image;

}

}

$newfile=UPLOAD_DIR."/icons/".md5($_SESSION['USER']->email).".jpg";//上传文件保存的目录

$image=newSimpleImage();

$image->load($_FILES['icons']['tmp_name']);//上传的临时文件名

$image->resizeToWidth(80);设置宽度

$image->save($newfile);

?>

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