Rewriting URL's in codeigniter with url_title()?

I am rewriting my website with codeigniter and have something I want to do but not sure it is possible.

I have a gallery on my site powered by the Flickr API. Here is an example of the code I use to display the Landscape pictures:

<?php foreach ($landscapes->photoset->photo as $l->photoset->photo) : ?>  
  <a href="<?=$l->photoset->photo->farm?>/<?=$l->photoset->photo->server?>/<?=$l->photoset->photo->id?>/<?=$l->photoset->photo->secret?>/<?=$l->photoset->photo->title?>">  
    <img class="f_thumb" src="<?=$l->photoset->photo->farm?>.static.flickr.com/<?=$l->photoset->photo->server?>/<?=$l->photoset->photo->id ?>_<?=$l->photoset->photo->secret ?>_s.jpg" title="<?=$l->photoset->photo->title?>" alt="<?=$l->photoset->photo->title?>" />
  </a>  
<?php endforeach; ?>

As you can see when a user clicks on a picture I pass over the Farm, Server, ID, Secret and Title elements using URI segments and build the page in the controller using

$data['farm'] = $this->uri->segment(3); 
$data['server'] = $this->uri->segment(4); 
$data['id'] = $this->uri->segment(5); 
$data['secret'] = $this->uri->segment(6);
$data['title'] = $this->uri->segment(7);

Everything works and is fine, but the URL’s are a tad long. Example:

http://localhost:8888/wip/index.php/gallery/focus/3/2682/4368875046/e8f97f61d9/Old_Mill_House_in_Donegal

Is there a way to rewrite the URL so its more like:

http://localhost:8888/wip/index.php/gallery/focus/Old_Mill_House_in_Do开发者_JAVA百科negal

I was looking at using:

$url_title = $this->uri->segment(7);
$url_title = url_title($url_title, 'underscore', TRUE);

But I can’t seem to be able to get it to work. Any ideas?

---

Are the links linking internally? Or are they linking to flickr? If it's internally, I'd suppose you could pass all the requisite information via POST. If it's to flickr, I don't think there is a way you can control how they want requests to come in for a specific item.

What's the endgame/purpose of all that extra info (secret, server, etc)?