本文实例为大家详细介绍了php实现图片上传、剪切功能的具体代码，供大家参考，具体内容如下

<?php

defined('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);

    }

  }

}

以上就是本文的全部内容，希望对大家学习php程序设计有所帮助。