php生成图片缩略图代码类

<?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("thumb.PHP");
    $cm=new CreatMiniature();
    $cm->SetVar("1.jpg","file");
    $cm->Distortion("dis_bei.jpg",150,200);
    $cm->Prorate("pro_bei.jpg",200);
    $cm->Cut("cut_bei.jpg",200);
    $cm->BackFill("fill_bei.jpg",200);

***************************************/

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($this->im,$toH,$this->srcW,$this->srcH);
        return $this->EchoImage($cImg,$toFile);
        ImageDestroy($cImg);
    }

    //生成按比例缩放的缩图
    function Prorate($toFile,$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,$ftoH,$this->srcH);
            return $this->EchoImage($cImg,$toFile);
            ImageDestroy($cImg);
        }
        else
        {
            $cImg=$this->CreatImage($this->im,$this->srcH,$toFile);
            ImageDestroy($cImg);
        }
    }

    //生成最小裁剪后的缩图
    function Cut($toFile,$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,$ctoH,$this->srcH);
        $cImg=$this->CreatImage($allImg,($ctoW-$toW)/2,($ctoH-$toH)/2,$toH);
        return $this->EchoImage($cImg,$toFile);
        ImageDestroy($cImg);
        ImageDestroy($allImg);
    }

    //生成背景填充的缩图
    function BackFill($toFile,$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,$backcolor);
        if($this->srcW>$toW||$this->srcH>$toH)
        {     
            $proImg=$this->CreatImage($this->im,$this->srcH);
            /*
             if($ftoW< $toW)
             {
                 ImageCopyMerge($cImg,$proImg,($toW-$ftoW)/2,100);
             }
             else if($ftoH<$toH)
             {
                 ImageCopyMerge($cImg,($toH-$ftoH)/2,100);
             }
             */
            if($ftoW<$toW)
            {
                 ImageCopy($cImg,$ftoH);
            }
            else if($ftoH<$toH)
            {
                 ImageCopy($cImg,$ftoH);
            }
            else
            {
                 ImageCopy($cImg,$ftoH);
            } 
        }
        else
        {
             ImageCopyMerge($cImg,$this->im,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,$img,$srcImgH);
            else
            {
                $creatImg=ImageCreate($creatW,$creatH);
                ImageCopyResized($creatImg,$srcImgH);
            }
         }
         else
         {
            $creatImg=ImageCreate($creatW,$creatH);
            ImageCopyResized($creatImg,$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;
        }
    }

}
?>