智能的PHP缩图类

<?php
/***************************************
*作者：落梦天蝎（beluckly）
*完成时间：2006-12-18
*类名：CreatMiniature
*功能：生成多种类型的缩略图
*基本参数：$srcFile,$echoType
*方法用到的参数：
                $toFile,生成的文件
                $toW,生成的宽
                $toH,生成的高
                $bk1,背景颜色参数 以255为最高
                $bk2,背景颜色参数
                $bk3,背景颜色参数
 
*例子：
 
    include(&quot;thumb.php&quot;);
    $cm=new CreatMiniature();
    $cm-&gt;SetVar(&quot;1.jpg&quot;,&quot;file&quot;);
    $cm-&gt;Distortion(&quot;dis_bei.jpg&quot;,150,200);
    $cm-&gt;Prorate(&quot;pro_bei.jpg&quot;,150,200);
    $cm-&gt;Cut(&quot;cut_bei.jpg&quot;,150,200);
    $cm-&gt;BackFill(&quot;fill_bei.jpg&quot;,150,200);
 
***************************************/
 
class CreatMiniature
{
    //公共变量
    var $srcFile=&quot;&quot;;        //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=&quot;&quot;;                //临时变量
    var $srcW=&quot;&quot;;            //原图宽
    var $srcH=&quot;&quot;;            //原图高
 
    //设置变量及初始化
    function SetVar($srcFile,$echoType)
    {
        $this-&gt;srcFile=$srcFile;
        $this-&gt;echoType=$echoType;
 
        $info = &quot;&quot;;
        $data = GetImageSize($this-&gt;srcFile,$info);
        switch ($data[2]) 
        {
         case 1:
           if(!function_exists(&quot;imagecreatefromgif&quot;)){
            echo &quot;你的GD库不能使用GIF格式的图片，请使用Jpeg或PNG格式！&lt;a href=&#39;javascript:go(-1);&#39;&gt;返回&lt;/a&gt;&quot;;
            exit();
           }
           $this-&gt;im = ImageCreateFromGIF($this-&gt;srcFile);
           break;
        case 2:
          if(!function_exists(&quot;imagecreatefromjpeg&quot;)){
           echo &quot;你的GD库不能使用jpeg格式的图片，请使用其它格式的图片！&lt;a href=&#39;javascript:go(-1);&#39;&gt;返回&lt;/a&gt;&quot;;
           exit();
          }
          $this-&gt;im = ImageCreateFromJpeg($this-&gt;srcFile);    
          break;
        case 3:
          $this-&gt;im = ImageCreateFromPNG($this-&gt;srcFile);    
          break;
      }
      $this-&gt;srcW=ImageSX($this-&gt;im);
      $this-&gt;srcH=ImageSY($this-&gt;im); 
    }
    
    //生成扭曲型缩图
    function Distortion($toFile,$toW,$toH)
    {
        $cImg=$this-&gt;CreatImage($this-&gt;im,$toW,$toH,0,0,0,0,$this-&gt;srcW,$this-&gt;srcH);
        return $this-&gt;EchoImage($cImg,$toFile);
        ImageDestroy($cImg);
    }
    
    //生成按比例缩放的缩图
    function Prorate($toFile,$toW,$toH)
    {
        $toWH=$toW/$toH;
        $srcWH=$this-&gt;srcW/$this-&gt;srcH;
        if($toWH&lt; =$srcWH)
        {
            $ftoW=$toW;
            $ftoH=$ftoW*($this-&gt;srcH/$this-&gt;srcW);
        }
        else
        {
              $ftoH=$toH;
              $ftoW=$ftoH*($this-&gt;srcW/$this-&gt;srcH);
        }
        if($this-&gt;srcW&gt;$toW||$this-&gt;srcH&gt;$toH)
        {
            $cImg=$this-&gt;CreatImage($this-&gt;im,$ftoW,$ftoH,0,0,0,0,$this-&gt;srcW,$this-&gt;srcH);
            return $this-&gt;EchoImage($cImg,$toFile);
            ImageDestroy($cImg);
        }
        else
        {
            $cImg=$this-&gt;CreatImage($this-&gt;im,$this-&gt;srcW,$this-&gt;srcH,0,0,0,0,$this-&gt;srcW,$this-&gt;srcH);
            return $this-&gt;EchoImage($cImg,$toFile);
            ImageDestroy($cImg);
        }
    }
    
    //生成最小裁剪后的缩图
    function Cut($toFile,$toW,$toH)
    {
          $toWH=$toW/$toH;
          $srcWH=$this-&gt;srcW/$this-&gt;srcH;
          if($toWH&lt; =$srcWH)
          {
               $ctoH=$toH;
               $ctoW=$ctoH*($this-&gt;srcW/$this-&gt;srcH);
          }
          else
          {
              $ctoW=$toW;
              $ctoH=$ctoW*($this-&gt;srcH/$this-&gt;srcW);
          } 
        $allImg=$this-&gt;CreatImage($this-&gt;im,$ctoW,$ctoH,0,0,0,0,$this-&gt;srcW,$this-&gt;srcH);
        $cImg=$this-&gt;CreatImage($allImg,$toW,$toH,0,0,($ctoW-$toW)/2,($ctoH-$toH)/2,$toW,$toH);
        return $this-&gt;EchoImage($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-&gt;srcW/$this-&gt;srcH;
        if($toWH&lt; =$srcWH)
        {
            $ftoW=$toW;
            $ftoH=$ftoW*($this-&gt;srcH/$this-&gt;srcW);
        }
        else
        {
              $ftoH=$toH;
              $ftoW=$ftoH*($this-&gt;srcW/$this-&gt;srcH);
        }
        if(function_exists(&quot;imagecreatetruecolor&quot;))
        {
            @$cImg=ImageCreateTrueColor($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-&gt;srcW&gt;$toW||$this-&gt;srcH&gt;$toH)
        {     
            $proImg=$this-&gt;CreatImage($this-&gt;im,$ftoW,$ftoH,0,0,0,0,$this-&gt;srcW,$this-&gt;srcH);
            /*
             if($ftoW&lt; $toW)
             {
                 ImageCopyMerge($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH,100);
             }
             else if($ftoH&lt;$toH)
             {
                 ImageCopyMerge($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
             }
             */
            if($ftoW&lt;$toW)
            {
                 ImageCopy($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH);
            }
            else if($ftoH&lt;$toH)
            {
                 ImageCopy($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH);
            }
            else
            {
                 ImageCopy($cImg,$proImg,0,0,0,0,$ftoW,$ftoH);
            } 
        }
        else
        {
             ImageCopyMerge($cImg,$this-&gt;im,($toW-$ftoW)/2,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
        }
        return $this-&gt;EchoImage($cImg,$toFile);
        ImageDestroy($cImg);
    }
    
 
    function CreatImage($img,$creatW,$creatH,$dstX,$dstY,$srcX,$srcY,$srcImgW,$srcImgH)
    {
        if(function_exists(&quot;imagecreatetruecolor&quot;))
        {
            @$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($this-&gt;echoType)
        {
            case &quot;link&quot;:
                if(function_exists(&#39;imagejpeg&#39;)) return ImageJpeg($img);
                else return ImagePNG($img);
                break;
            case &quot;file&quot;:
                if(function_exists(&#39;imagejpeg&#39;)) return ImageJpeg($img,$to_File);
                else return ImagePNG($img,$to_File);
                break;
        }
    }
 
}
?>