/**   * desription 判断是否gif动画   * @param sting $image_file图片路径   * @return boolean t 是 f 否   */  function check_gifcartoon($image_file){    $fp = fopen($image_file,'rb');    $image_head = fread($fp,1024);    fclose($fp);    return preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;  }   /**  * desription 压缩图片  * @param sting $imgsrc 图片路径  * @param string $imgdst 压缩后保存路径  */  function compressed_image($imgsrc,$imgdst){    list($width,$height,$type)=getimagesize($imgsrc);    $new_width = ($width>600?600:$width)*0.9;    $new_height =($height>600?600:$height)*0.9;    switch($type){      case 1:        $giftype=check_gifcartoon($imgsrc);        if($giftype){          header('Content-Type:image/gif');          $image_wp=imagecreatetruecolor($new_width, $new_height);          $image = imagecreatefromgif($imgsrc);          imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);          //75代表的是质量、压缩图片容量大小          imagejpeg($image_wp, $imgdst,75);          imagedestroy($image_wp);        }        break;      case 2:        header('Content-Type:image/jpeg');        $image_wp=imagecreatetruecolor($new_width, $new_height);        $image = imagecreatefromjpeg($imgsrc);        imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);        //75代表的是质量、压缩图片容量大小        imagejpeg($image_wp, $imgdst,75);        imagedestroy($image_wp);        break;      case 3:        header('Content-Type:image/png');        $image_wp=imagecreatetruecolor($new_width, $new_height);        $image = imagecreatefrompng($imgsrc);        imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);        //75代表的是质量、压缩图片容量大小        imagejpeg($image_wp, $imgdst,75);        imagedestroy($image_wp);        break;    }  }