php 圖片處理方法 縮略和剪切

<?
//圖片縮放類

class resizep_w_picpath
{
   //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;
   //目標圖象地址[separator]
   var $dstimg;
   //臨時建立的圖象
   var $im;

function resizep_w_picpath($img, $wid, $hei,$c)
   {
       $this->srcimg = $img;
       $this->resize_width = $wid;
       $this->resize_height = $hei;
       $this->cut = $c;
       //圖片的類型
       $this->type = substr(strrchr($this->srcimg,"."),1);
       //初始化圖象
       $this->initi_img();
       //目標圖象地址
       $this -> dst_img();
       //--
       $this->width = p_w_picpathsx($this->im);
       $this->height = p_w_picpathsy($this->im);
       //生成圖象
       $this->newimg();
       ImageDestroy ($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
           {
               $newimg = p_w_picpathcreatetruecolor($this->resize_width,$this->resize_height);
               p_w_picpathcopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           }
           if($ratio<$resize_ratio)
           //寬度優先
           {
               $newimg = p_w_picpathcreatetruecolor($this->resize_width,$this->resize_height);
               p_w_picpathcopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio));
               ImageJpeg ($newimg,$this->dstimg);
           }
       }
       else
       //不裁圖
       {
           if($ratio>=$resize_ratio)
           {
               $newimg = p_w_picpathcreatetruecolor($this->resize_width,($this->resize_width)/$ratio);
               p_w_picpathcopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           }
           if($ratio<$resize_ratio)
           {
               $newimg = p_w_picpathcreatetruecolor(($this->resize_height)*$ratio,$this->resize_height);
               p_w_picpathcopyresampled($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height)*$ratio, $this->resize_height, $this->width, $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           }
       }
   }
   //初始化圖象
   function initi_img()
   {
       if($this->type=="jpg")
       {
           $this->im = p_w_picpathcreatefromjpeg($this->srcimg);
       }
       if($this->type=="gif")
       {
           $this->im = p_w_picpathcreatefromgif($this->srcimg);
       }
       if($this->type=="png")
       {
           $this->im = p_w_picpathcreatefrompng($this->srcimg);
       }
   }
   //圖象目標地址
   function dst_img()
   {
       $full_length = strlen($this->srcimg);
       $type_length = strlen($this->type);
       $name_length = $full_length-$type_length;
       $name         = substr($this->srcimg,0,$name_length-1);
       $this->dstimg = $name."_s.".$this->type;
   }
}

$resizep_w_picpath = new resizep_w_picpath("test.jpg", "360", "360", "0"); //生成新的圖片爲 test_s.jpg
?>
<img src="test_s.jpg" border="0">