在codeigniter中上传特定宽度和高度的图片

$this->load->library('upload');
$this->load->library('image_lib');

$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = 2048;
$this->upload->initialize($config);

if (!$this->upload->do_upload('image')) {
    $error = $this->upload->display_errors();
    // 处理上传失败的情况
} else {
    $data = $this->upload->data();
    $image_path = $data['full_path'];
    // 处理上传成功的情况
}

$this->image_lib->clear();
$this->image_lib->initialize(array('image_library' => 'gd2'));

$config['source_image'] = $image_path;
$config['new_image'] = './uploads/resized/';
$config['maintain_ratio'] = TRUE;
$config['width'] = $desired_width;
$config['height'] = $desired_height;
$this->image_lib->initialize($config);

if (!$this->image_lib->resize()) {
    $error = $this->image_lib->display_errors();
    // 处理调整尺寸失败的情况
} else {
    $resized_image_path = $config['new_image'] . $data['file_name'];
    // 处理调整尺寸成功的情况
}