該如何去調用這個類

該怎麼去調用這個類？

/*
圖片處理類：縮減，裁剪，圓角，傾斜
*/
class resizeimage
{
   //圖片類型
   var $type;
   //實際寬度
   var $width;
   //實際高度
   var $height;
   //改變後的寬度
   var $resize_width;
   //改變後的高度
   var $resize_height;
   //是否裁圖
   var $cut;
   //源圖象
   var $srcimg;
   //靶心圖表象地址
   var $dstimg;
   //圓角源
   var $corner;
   var $im;
function resizeimage($img, $corner, $wid, $hei,$c, $corner_radius, $angle)
   {
       $this->srcimg = $img;
    $this->corner = $corner;
       $this->resize_width = $wid;
       $this->resize_height = $hei;
       $this->cut = $c;
    $this->corner_radius = $corner_radius;
    $this->angle = $angle;
       //圖片的類型
       $this->type = substr(strrchr($this->srcimg,"."),1);
       //初始化圖象
       $this->initi_img();
       //靶心圖表象地址
       $this -> dst_img();
       //--
       $this->width = imagesx($this->im);
       $this->height = imagesy($this->im);
       //產生圖象
       $this->newimg();
       ImageDestroy ($this->im);
   }
   function newimg()
   {
       //改變後的圖象的比例
       $resize_ratio = ($this->resize_width)/($this->resize_height);
       //實際圖象的比例
       $ratio = ($this->width)/($this->height);
       if(($this->cut)=="1")
       //裁圖
       {
           if($ratio>=$resize_ratio)
           //高度優先
           {
               $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height);
      $tmp = $this->rounded_corner($newimg,$this->resize_width);
               imagepng ($tmp,$this->dstimg);
           }
           if($ratio<$resize_ratio)
           //寬度優先
           {
               $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio));
      $tmp = $this->rounded_corner($newimg);
               imagepng ($tmp,$this->dstimg);
           }
       }
       else
       //不裁圖
       {
           if($ratio>=$resize_ratio)
           {
               $newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           } 
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