title: codeigniter captcha helper is not increasing text font size
body: <p>This seems a duplace question some how, but its not.
  Am asking the following : </p>
  
  <ol>
  <li><p>Does the codeingiter helper does have a font size increasing feature ? even if i passed the following array setting seems not change.</p>
  
  <p>'font_size' => 36 </p></li>
  </ol>
  
  <p>2.The font i used has the following font sizes , but still no change to captcah size</p>
  
  <p><img src="https://i.stack.imgur.com/EIFZM.png" alt="enter image description here"></p>
  
  <p>So what is the matter ?</p>
  
  <pre><code>/* Setup config to pass into the create_captcha function */
                  $capache_config = array(
                      'img_path' =&gt; 'captcha/',
                      'img_url' =&gt; base_url() . 'captcha/',
                      'img_width' =&gt; '150',
                      'font_path' =&gt; base_url() . 'captcha/font/captcha4.ttf',
                      'img_height' =&gt; 40,
                      'expiration' =&gt; 7200
                  );
  
                  /* Generate the captcha */
                  $captcha = create_captcha($capache_config);
  </code></pre>
  
  <p>But the size is i can't get it larger even if i increased width or height ? 
  Any thing you know about this ?</p>
  
  <p><img src="https://i.stack.imgur.com/UlTnS.png" alt="enter image description here"></p>