$this->load->library('image_lib');
$config['image_library'] = 'gd2';
$config['upload_path'] = './assets/uploads';
$config['allowed_types'] = 'gif|jpg|png|jpeg';
$config['create_thumb'] = TRUE;
$config['maintain_ratio'] = TRUE;
$config['quality'] = '60%';
$config['width'] = 200;
$config['height'] = 200;
$this->load->library('image_lib', $config);
$this->load->library('upload', $config);
$this->image_lib->resize()

if ($this->upload->do_upload('resim')) {

    $data_upload_files = $this->upload->data();
    $image = $data_upload_files['file_name'];
} else {
     // echo $this->upload->display_errors('<p>', '</p>');

}

$config['upload_path'] = './assets/uploads';
$config['allowed_types'] = 'gif|jpg|png|jpeg';
$this->load->library('upload', $config);
if ($this->upload->do_upload('resim')) {
    $file_data = $this->upload->data();
    $resize['image_library'] = 'gd2';
    $resize['create_thumb'] = TRUE;
    $resize['maintain_ratio'] = TRUE;
    $resize['quality'] = '60%';
    $resize['width'] = 200;
    $resize['height'] = 200;
    $resize['source_image'] = $file_data['full_path'];
    $this->load->library('image_lib', $resize);
    if (!$this->image_lib->resize()) {
        echo $this->image_lib->display_errors();
    }
} else {
    echo $this->upload->display_errors('<p>', '</p>');
}