Я пытаюсь загрузить изображения и изменить их размер в разных измерениях в рамках одной и той же функции. но то, что происходит, - то, что только один изменяет размер, а другие нет. Мой код:

    function do_upload()
{
    $this_user = $this->auth->info;if(!is_dir('./uploads/'.$this_user->username)){
        mkdir('./uploads/'.$this_user->username);
        mkdir('./uploads/'.$this_user->username.'/photos');
        mkdir('./uploads/'.$this_user->username.'/photos/master');
        mkdir('./uploads/'.$this_user->username.'/photos/small');
        mkdir('./uploads/'.$this_user->username.'/photos/medium');
        mkdir('./uploads/'.$this_user->username.'/photos/large');
        mkdir('./uploads/'.$this_user->username.'/photos/xlarge');
    }
    $config['upload_path'] = './uploads/'.$this_user->username.'/photos/master/';
    $config['allowed_types'] = 'gif|jpg';

    $title = $this->input->post('title');
    $this->load->library('upload', $config);
    if ( ! $this->upload->do_upload())
    {
        echo '<div id="status">error</div>';
        echo '<div id="message">'. $this->upload->display_errors() .'</div>';
    }
    else
    {
        $data = array('upload_data' => $this->upload->data());
        //resizing begins
            $image_width = $data['upload_data']['image_width'];
            $image_height = $data['upload_data']['image_height'];
            $full_path = $data['upload_data']['full_path'];
            //checking for width
            if($image_width>5000){
                $config['image_library'] = 'gd2';
                $config['source_image'] = $full_path;
                //$config['create_thumb'] = TRUE;
                $config['maintain_ratio'] = TRUE;
                $config['width'] = 5000;
                //$config['height'] = 50;
                $config['new_image'] = './uploads/'.$this_user->username.'/photos/xlarge';
                $this->load->library('image_lib', $config);
                $this->image_lib->resize();
            }
            if($image_width>=4500){
                $config['image_library'] = 'gd2';
                $config['source_image'] = $full_path;
                //$config['create_thumb'] = TRUE;
                $config['maintain_ratio'] = TRUE;
                $config['width'] = 4500;
                //$config['height'] = 50;
                $config['new_image'] = './uploads/'.$this_user->username.'/photos/large';
                $this->load->library('image_lib', $config);
                $this->image_lib->resize();
            }
            if($image_width>=2000){
                $config['image_library'] = 'gd2';
                $config['source_image'] = $full_path;
                //$config['create_thumb'] = TRUE;
                $config['maintain_ratio'] = TRUE;
                $config['width'] = 2000;
                //$config['height'] = 50;
                $config['new_image'] = './uploads/'.$this_user->username.'/photos/medium';
                $this->load->library('image_lib', $config);
                $this->image_lib->resize();
            }
            if($image_width>=800){
                $config['image_library'] = 'gd2';
                $config['source_image'] = $full_path;
                //$config['create_thumb'] = TRUE;
                $config['maintain_ratio'] = TRUE;
                $config['width'] = 800;
                //$config['height'] = 50;
                $config['new_image'] = './uploads/'.$this_user->username.'/photos/small';
                $this->load->library('image_lib', $config);
                $this->image_lib->resize();
            }
        //resizing ends
        echo '<div id="status">success</div>';
        //then output your message (optional)
        echo '<div id="message">'. $data['upload_data']['file_name'].$this->input->post('type').' Successfully uploaded.</div>';
        //pass the data to js
        echo '<div id="upload_data">'. json_encode($data) . '</div>';

    }
}

Что я здесь не так делаю?