How to resize image using Codeigniter

Question

thanks guys but i solve this problem. via loading library in constructor

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

after that added two line code

 $this->image_lib->clear();
 $this->image_lib->initialize($img_array);

and remove this line

 $this->load->library('image_lib', $img_array);

my final code is

public function add_images(){

    $this->form_validation->set_rules('description','Description','required');
    $this->form_validation->set_rules('status','Status','required');

    if($this->form_validation->run() == TRUE) {
         // print_r($this->input->post());
        $config['upload_path'] = 'public/img/inner_images/';
        $config['allowed_types'] = 'gif|jpg|jpeg|png';   // upload only valid images            
        // update library setting of upload
        $this->load->library('upload', $config);
        //upload image 
        $this->upload->do_upload('image');
        $fInfo = $this->upload->data(); // get all info of uploaded file

        //for image resize
        $img_array = array();
        $img_array['image_library'] = 'gd2';
        $img_array['maintain_ratio'] = TRUE;
        $img_array['create_thumb'] = TRUE;
        //you need this setting to tell the image lib which image to process
        $img_array['source_image'] = $fInfo['full_path'];
        $img_array['width'] = 113;
        $img_array['height'] = 75;

        $this->image_lib->clear(); // added this line
        $this->image_lib->initialize($img_array); // added this line
        if (!$this->image_lib->resize())
        {
            echo $this->image_lib->display_errors(); exit;
        }
        if($fInfo['file_ext'] ==='.gif'||$fInfo['file_ext'] ==='.jpg'|| $fInfo['file_ext'] ==='.jpeg' || $fInfo['file_ext'] ==='.png'|| $fInfo['file_ext'] ===''){
            $insert = array(
                'inner_image' =>$fInfo['file_name'],
                'description' => $this->input->post('description'),
                'status' => $this->input->post('status')
            );
            $check = $this->mdl_inner->add_image($insert);
            if($check){
                $this->session->set_flashdata('success',"Image Added Sucessfully");
                redirect('admin/inner_gallery/add_images/', 'refresh');  
            }
        }else{
            $this->session->set_flashdata('error',"Upload Proper Image Format");
            redirect('admin/inner_gallery/add_images/', 'refresh');
        }
    }
    $arrData['middle'] = 'admin/inner/add_image';
    $this->load->view('admin/template',$arrData);
}