这样子在本地环境就可以直接测试使用。

<?php
class CreatMiniature
{
//公共变量
var $srcFile=””;        //原图
var $echoType;            //输出图片类型，link–不保存为文件；file–保存为文件
var $im=””;                //临时变量
var $srcW=””;            //原图宽
var $srcH=””;            //原图高

//设置变量及初始化
function SetVar($srcFile,$echoType)
{
$this->srcFile=$srcFile;
$this->echoType=$echoType;

$info = “”;
$data = GetImageSize($this->srcFile,$info);
switch ($data[2])
{
case 1:
if(!function_exists(“imagecreatefromgif”)){
echo “你的GD库不能使用GIF格式的图片，请使用Jpeg或PNG格式！<a href=’javascript:go(-1);’>返回</a>”;
exit();
}
$this->im = ImageCreateFromGIF($this->srcFile);
break;
case 2:
if(!function_exists(“imagecreatefromjpeg”)){
echo “你的GD库不能使用jpeg格式的图片，请使用其它格式的图片！<a href=’javascript:go(-1);’>返回</a>”;
exit();
}
$this->im = ImageCreateFromJpeg($this->srcFile);
break;
case 3:
$this->im = ImageCreateFromPNG($this->srcFile);
break;
}
$this->srcW=ImageSX($this->im);
$this->srcH=ImageSY($this->im);
}

//生成扭曲型缩图
function Distortion($toFile,$toW,$toH)
{
$cImg=$this->CreatImage($this->im,$toW,$toH,0,0,0,0,$this->srcW,$this->srcH);
return $this->EchoImage($cImg,$toFile);
ImageDestroy($cImg);
}

//生成按比例缩放的缩图
function Prorate($toFile,$toW,$toH)
{
$toWH=$toW/$toH;
$srcWH=$this->srcW/$this->srcH;
if($toWH<=$srcWH)
{
$ftoW=$toW;
$ftoH=$ftoW*($this->srcH/$this->srcW);
}
else
{
$ftoH=$toH;
$ftoW=$ftoH*($this->srcW/$this->srcH);
}
if($this->srcW>$toW||$this->srcH>$toH)
{
$cImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);
return $this->EchoImage($cImg,$toFile);
ImageDestroy($cImg);
}
else
{
$cImg=$this->CreatImage($this->im,$this->srcW,$this->srcH,0,0,0,0,$this->srcW,$this->srcH);
return $this->EchoImage($cImg,$toFile);
ImageDestroy($cImg);
}
}

//生成最小裁剪后的缩图
function Cut($toFile,$toW,$toH)
{
$toWH=$toW/$toH;
$srcWH=$this->srcW/$this->srcH;
if($toWH<=$srcWH)
{
$ctoH=$toH;
$ctoW=$ctoH*($this->srcW/$this->srcH);
}
else
{
$ctoW=$toW;
$ctoH=$ctoW*($this->srcH/$this->srcW);
}
$allImg=$this->CreatImage($this->im,$ctoW,$ctoH,0,0,0,0,$this->srcW,$this->srcH);
$cImg=$this->CreatImage($allImg,$toW,$toH,0,0,($ctoW-$toW)/2,($ctoH-$toH)/2,$toW,$toH);
return $this->EchoImage($cImg,$toFile);
ImageDestroy($cImg);
ImageDestroy($allImg);
}

//生成背景填充的缩图
function BackFill($toFile,$toW,$toH,$bk1=255,$bk2=255,$bk3=255)
{
$toWH=$toW/$toH;
$srcWH=$this->srcW/$this->srcH;
if($toWH<=$srcWH)
{
$ftoW=$toW;
$ftoH=$ftoW*($this->srcH/$this->srcW);
}
else
{
$ftoH=$toH;
$ftoW=$ftoH*($this->srcW/$this->srcH);
}
if(function_exists(“imagecreatetruecolor”))
{
@$cImg=ImageCreateTrueColor($toW,$toH);
if(!$cImg)
{
$cImg=ImageCreate($toW,$toH);
}
}
else
{
$cImg=ImageCreate($toW,$toH);
}
$backcolor = imagecolorallocate($cImg, $bk1, $bk2, $bk3);        //填充的背景颜色
ImageFilledRectangle($cImg,0,0,$toW,$toH,$backcolor);
if($this->srcW>$toW||$this->srcH>$toH)
{
$proImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);
/*
if($ftoW<$toW)
{
ImageCopyMerge($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH,100);
}
else if($ftoH<$toH)
{
ImageCopyMerge($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
}
*/
if($ftoW<$toW)
{
ImageCopy($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH);
}
else if($ftoH<$toH)
{
ImageCopy($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH);
}
else
{
ImageCopy($cImg,$proImg,0,0,0,0,$ftoW,$ftoH);
}
}
else
{
ImageCopyMerge($cImg,$this->im,($toW-$ftoW)/2,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
}
return $this->EchoImage($cImg,$toFile);
ImageDestroy($cImg);
}

function CreatImage($img,$creatW,$creatH,$dstX,$dstY,$srcX,$srcY,$srcImgW,$srcImgH)
{
if(function_exists(“imagecreatetruecolor”))
{
@$creatImg = ImageCreateTrueColor($creatW,$creatH);
if($creatImg)
ImageCopyResampled($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
else
{
$creatImg=ImageCreate($creatW,$creatH);
ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
}
}
else
{
$creatImg=ImageCreate($creatW,$creatH);
ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
}
return $creatImg;
}

//输出图片，link—只输出，不保存文件。file–保存为文件
function EchoImage($img,$to_File)
{
switch($this->echoType)
{
case “link”:
if(function_exists(‘imagejpeg’)) return ImageJpeg($img);
else return ImagePNG($img);
break;
case “file”:
if(function_exists(‘imagejpeg’)) return ImageJpeg($img,$to_File);
else return ImagePNG($img,$to_File);
break;
}
}

}
?>
<?
if ($_POST[“action”]==”addnew”) {
$pxname=””;
if(!$_FILES[‘myphoto’][‘error’]){
$f=$_FILES[‘myphoto’];
$kzm=strtolower(trim(substr($f[‘name’],-4)));
if($kzm!=”.jpg” and $kzm!=”.gif” and $kzm!=”.png” and $kzm!=”.bmp”)
{
echo “<script>alert(‘图片格式不对!($kzm)’);location.href=’javascript:history.back()’;</script>”;
die;
}
$dest_dir=’images’;//设定上传目录
$pxname=date(“ymdhis”).”_”.”s”.substr($f[‘name’],-4);
$dest=$dest_dir.’/’.$pxname;//我这里设置文件名为日期加上文件名避免重复
$r=move_uploaded_file($f[‘tmp_name’],$dest);
chmod($dest, 0755);//设定上传的文件的属性
}

$cm=new CreatMiniature();
$cm->SetVar(“images/”.$pxname,”file”);
$cm->Prorate(“images/”.$pxname,150,200);
}
?>

<?
//使用示例
//    include(“thumb.php”);
//    $cm=new CreatMiniature();
//    $cm->SetVar(“1.jpg”,”file”);
//    $cm->Distortion(“dis_bei.jpg”,150,200);
//    $cm->Prorate(“pro_bei.jpg”,150,200);
//    $cm->Cut(“cut_bei.jpg”,150,200);
//    $cm->BackFill(“fill_bei.jpg”,150,200);</p>
?>

<p>&nbsp;</p>
<p>&nbsp;</p>
<form name=”form1″ enctype=”multipart/form-data” method=”post” action=””>
<input name=”myphoto” type=”file” id=”myphoto”>
<input type=”submit” name=”Submit” value=”提交”>
<input name=”action” type=”hidden” id=”action” value=”addnew”>
</form>
<p>&nbsp;</p>

*/

function bigtosmallimg($file,$path,$w=120,$h=90)
{
$img=$path.$file;
$imgarr=getimagesize($img);
$sw=$imgarr[0];//原图宽
$sh=$imgarr[1];//原图高
$stype=$imgarr[2];
//按比例缩放
if($sw/$sh>$w/$h){
$mw=$w;
$mh=(int)$sh*($w/$sw);
}
else{
$mw=(int)$sw*($h/$sh);
$mh=$h;
}

switch($stype){//根据上传好的图形文件类型新建一个用来生成缩略图的源文件。
case 1:
$srcf = imagecreatefromgif($img);
break;
case 2:
$srcf = imagecreatefromjpeg($img);
break;
case 3:
$srcf = imagecreatefrompng($img);
break;
default:
showmsg(‘程序调用错误。’);
break;
}

$desf =imagecreatetruecolor($mw,$mh);

imagecopyresampled($desf,$srcf,0,0,0,0,$mw,$mh,$sw,$sh);
$sm_name=$path.”s_”.$file;
switch($stype){
case 1:
imagegif($desf,$sm_name);
break;
case 2:
imagejpeg($desf,$sm_name);
break;
case 3:
imagepng($desf,$sm_name);
break;
default:
showmsg(‘无法生成’ . $stype . ‘的缩略图。’);
break;
}
imagedestroy($desf);
imagedestroy($srcf);

}

//此缩略图调用方法

bigtosmallimg($file,$path,$w=120,$h=90);
/*

$file = 图片的路径
$path = 生成后保存的路径
$w =图片宽度
$h =图片高度
*/

php常用图片处理类

<?
class image {
// 当前图片
protected $img;
// 图像types 对应表
protected $types = array(
1 => 'gif',
2 => 'jpg',
3 => 'png',
6 => 'bmp'
);

// image
public function __construct($img=”){
!$img && $this->param($img);
}

// Info
public function param($img){
$this->img = $img;
return $this;
}

// imageInfo
public function getImageInfo($img){
$info = @getimagesize($img);
if(isset($this->types[$info[2]])){
$info[‘ext’] = $info[‘type’] = $this->types[$info[2]];
} else{
$info[‘ext’] = $info[‘type’] = ‘jpg’;
}
$info[‘type’] == ‘jpg’ && $info[‘type’] = ‘jpeg’;
$info[‘size’] = @filesize($img);
return $info;
}

// thumb(新图地址, 宽, 高, 裁剪, 允许放大)
public function thumb($filename,$new_w=160,$new_h=120,$cut=0,$big=0){
// 获取原图信息
$info = $this->getImageInfo($this->img);
if(!emptyempty($info[0])) {
$old_w = $info[0];
$old_h = $info[1];
$type = $info[‘type’];
$ext = $info[‘ext’];
unset($info);
// 如果原图比缩略图小 并且不允许放大
if($old_w < $new_h && $old_h < $new_w && !$big){
return false;
}
// 裁剪图片
if($cut == 0){ // 等比列
$scale = min($new_w/$old_w, $new_h/$old_h); // 计算缩放比例
$width = (int)($old_w*$scale); // 缩略图尺寸
$height = (int)($old_h*$scale);
$start_w = $start_h = 0;
$end_w = $old_w;
$end_h = $old_h;
} elseif($cut == 1){ // center center 裁剪
$scale1 = round($new_w/$new_h,2);
$scale2 = round($old_w/$old_h,2);
if($scale1 > $scale2){
$end_h = round($old_w/$scale1,2);
$start_h = ($old_h–$end_h)/2;
$start_w = 0;
$end_w = $old_w;
} else{
$end_w = round($old_h*$scale1,2);
$start_w = ($old_w–$end_w)/2;
$start_h = 0;
$end_h = $old_h;
}
$width = $new_w;
$height= $new_h;
} elseif($cut == 2){ // left top 裁剪
$scale1 = round($new_w/$new_h,2);
$scale2 = round($old_w/$old_h,2);
if($scale1 > $scale2){
$end_h = round($old_w/$scale1,2);
$end_w = $old_w;
} else{
$end_w = round($old_h*$scale1,2);
$end_h = $old_h;
}
$start_w = 0;
$start_h = 0;
$width = $new_w;
$height= $new_h;
}
// 载入原图
$createFun = ‘ImageCreateFrom’.$type;
$oldimg = $createFun($this->img);
// 创建缩略图
if($type!=‘gif’ && function_exists(‘imagecreatetruecolor’)){
$newimg = imagecreatetruecolor($width, $height);
} else{
$newimg = imagecreate($width, $height);
}
// 复制图片
if(function_exists(“ImageCopyResampled”)){
ImageCopyResampled($newimg, $oldimg, 0, 0, $start_w, $start_h, $width, $height, $end_w,$end_h);
} else{
ImageCopyResized($newimg, $oldimg, 0, 0, $start_w, $start_h, $width, $height, $end_w,$end_h);
}

// 对jpeg图形设置隔行扫描
$type == ‘jpeg’ && imageinterlace($newimg,1);
// 生成图片
$imageFun = ‘image’.$type;
!@$imageFun($newimg,$filename) && die(‘保存失败!检查目录是否存在并且可写?’);
ImageDestroy($newimg);
ImageDestroy($oldimg);
return $filename;
}
return false;
}

// water(保存地址,水印图片,水印位置,透明度)
public function water($filename,$water,$pos=0,$pct=80){
// 加载水印图片
$info = $this->getImageInfo($water);
if(!emptyempty($info[0])){
$water_w = $info[0];
$water_h = $info[1];
$type = $info[‘type’];
$fun = ‘imagecreatefrom’.$type;
$waterimg = $fun($water);
} else{
return false;
}
// 加载背景图片
$info = $this->getImageInfo($this->img);
if(!emptyempty($info[0])){
$old_w = $info[0];
$old_h = $info[1];
$type = $info[‘type’];
$fun = ‘imagecreatefrom’.$type;
$oldimg = $fun($this->img);
} else{
return false;
}
// 剪切水印
$water_w >$old_w && $water_w = $old_w;
$water_h >$old_h && $water_h = $old_h;

// 水印位置
switch($pos){
case 0://随机
$posX = rand(0,($old_w – $water_w));
$posY = rand(0,($old_h – $water_h));
break;
case 1://1为顶端居左
$posX = 0;
$posY = 0;
break;
case 2://2为顶端居中
$posX = ($old_w – $water_w) / 2;
$posY = 0;
break;
case 3://3为顶端居右
$posX = $old_w – $water_w;
$posY = 0;
break;
case 4://4为中部居左
$posX = 0;
$posY = ($old_h – $water_h) / 2;
break;
case 5://5为中部居中
$posX = ($old_w – $water_w) / 2;
$posY = ($old_h – $water_h) / 2;
break;
case 6://6为中部居右
$posX = $old_w – $water_w;
$posY = ($old_h – $water_h) / 2;
break;
case 7://7为底端居左
$posX = 0;
$posY = $old_h – $water_h;
break;
case 8://8为底端居中
$posX = ($old_w – $water_w) / 2;
$posY = $old_h – $water_h;
break;
case 9://9为底端居右
$posX = $old_w – $water_w;
$posY = $old_h – $water_h;
break;
default: //随机
$posX = rand(0,($old_w – $water_w));
$posY = rand(0,($old_h – $water_h));
break;
}
// 设定图像的混色模式
imagealphablending($oldimg, true);
// 添加水印
imagecopymerge($oldimg, $waterimg, $posX, $posY, 0, 0, $water_w,$water_h,$pct);
$fun = ‘image’.$type;
!@$fun($oldimg, $filename) && die(‘保存失败!检查目录是否存在并且可写?’);
imagedestroy($oldimg);
imagedestroy($waterimg);
return $filename;
}
}
?>

检测文件是否图片

<?
function file_is_valid_image($path) {
$size = @getimagesize($path);
return !empty($size);
}

?>

]]>