PHP按一定比例压缩图片的方法

<?php
/**
 图片压缩操作类
 v1.0
*/
  class Image{
  
  private $src;
  private $imageinfo;
  private $image;
  public $percent = 0.1;
  public function __construct($src){
   
   $this->src = $src;
   
  }
  /**
  打开图片
  */
  public function openImage(){
   
   list($width, $height, $type, $attr) = getimagesize($this->src);
   $this->imageinfo = array(
  
  'width'=>$width,
  'height'=>$height,
  'type'=>image_type_to_extension($type,false),
  'attr'=>$attr
   );
   $fun = "imagecreatefrom".$this->imageinfo['type'];
   $this->image = $fun($this->src);
  }
  /**
  操作图片
  */
  public function thumpImage(){
   
   $new_width = $this->imageinfo['width'] * $this->percent;
  $new_height = $this->imageinfo['height'] * $this->percent;
  $image_thump = imagecreatetruecolor($new_width,$new_height);
  //将原图复制带图片载体上面，并且按照一定比例压缩,极大的保持了清晰度
  imagecopyresampled($image_thump,$this->image,0,0,0,0,$new_width,$new_height,$this->imageinfo['width'],$this->imageinfo['height']);
  imagedestroy($this->image); 
  $this->image = $image_thump;
  }
  /**
  输出图片
  */
  public function showImage(){
   
   header('Content-Type: image/'.$this->imageinfo['type']);
  $funcs = "image".$this->imageinfo['type'];
  $funcs($this->image);
   
  }
  /**
  保存图片到硬盘
  */
  public function saveImage($name){
   
   $funcs = "image".$this->imageinfo['type'];
  $funcs($this->image,$name.'.'.$this->imageinfo['type']);
   
  }
  /**
  销毁图片
  */
  public function __destruct(){
   
   imagedestroy($this->image);
  }
  
  }
 
 
?>

<?php
 
 require 'image.class.php';
 $src = "001.jpg";
 $image = new Image($src);
 $image->percent = 0.2;
 $image->openImage();
 $image->thumpImage();
 $image->showImage();
 $image->saveImage(md5("aa123"));
 
 
?>