php实现图片上传、剪切功能

<?phpdefined('BASEPATH') OR exit('No direct script access allowed'); class Index extends MY_Controller {  function __construct(){    parent::__construct();    $this->load->helper(array('form', 'url'));  }   /**   * 首页   */  public function index() {    $this->load->view('upload_form', array('error' => ' ' ));  }        public function do_upload()  {    $config['upload_path']   = './data/uploads/';    $config['allowed_types']  = 'gif|jpg|png';    $config['max_size']   = 100;    $config['max_width']    = 1024;    $config['max_height']    = 768;     $this->load->library('upload', $config);     if ( ! $this->upload->do_upload('userfile'))    {      $error = array('error' => $this->upload->display_errors());       $this->load->view('upload_form', $error);    }    else    {      $data = array('upload_data' => $this->upload->data());             $this->load->library('image_lib');            list($width, $height) = getimagesize($data['upload_data']['full_path']);      $config['image_library'] = 'gd2';      $config['source_image'] = $data['upload_data']['full_path'];      $config['maintain_ratio'] = TRUE;      if($width >= $height)      {        $config['master_dim'] = 'height';      }else{        $config['master_dim'] = 'width';      }      $config['width'] = 180;      $config['height'] = 180;      $this->image_lib->initialize($config);      $this->image_lib->resize();           $config['maintain_ratio'] = FALSE;      if($width >= $height)      {        $config['x_axis'] = floor(($width * 180 / $height - 180)/2);      }else{        $config['y_axis'] = floor(($height * 180 / $width - 180)/2);      }      $this->image_lib->initialize($config);      $this->image_lib->crop();             $this->load->view('upload_success', $data);    }  }}