Get Original Image File Name + Extenstion

I have added fancybox to my site and I want to use it in the album view for a slideshow of the album photos.  I have added the link to the file brows_unit.html

<div class="sys_file_search_title"><a class="image_group" rel="this_group" href="{imageOrig}" title="{title}">View in Slideshow</a></div>

That adds a link for fancybox to work off of for each image on the page.

In the file BxBaseSearchResultSharedMedia.php I added the following that is incomplete:

$aUnit['imageOrig'] = 'm/photos/get_image/original/' . file name . file ext

What I need to know is how to get the file name and extension (I allow png files to be stored) for the original image  to complete the path for the link;   I know it is stored using a hash and not the uploaded file name.

I have yet to get this implemented.

$aUnit['imageOrig'] = 'm/photos/get_image/original/' .$FileName

How to get $FileName which would include the hash of the original file name + extension of the file

OK, I am continuing to bang away at this with a sledge hammer hoping I can learn a bit more about Dolphin.  I saw the function, getImageUrl() but that returns the ID of the image and not the image name.  I did guess that setting $sImgType equal to original would point to the original file folder.  Can I retrieve the name from the ID without doing a database search?

I noticed the thumbnail image; which has the name of the file, is loaded in as the background of the division.  That uses style="background-image: url('__img_url__')  Can I access this  __img_url__ in some manner?  The more I play with Dolphin, the more I realise I don't know anything.

$aUnit['imageOrig'] = $this->getImgUrl($aData['id'], $sImgType = 'original'); 

OK, I see I am completely lost in this, getImgUrl($aData['id'], $sImgType = 'original') does not do what I thought it did; whatever is in  $aData['id'] just gets put into the return string. 

 Is there a function where I can put in the id of the image and have it return the original file URL?

I am going to try working from the thumbnail side of things. 

Let's look at it from this angle.  I want the same function of "view original" that is on the photo page view for the album view where you see each thumbnail of the images.  See, if I can put a link with each thumbnail to the original image file-name plus file-extension because not every image is a jpeg, some are pngs, I can then use fancybox to have a really nice slideshow in a lightbox.  Easy peasy if I can find the blasted way to get the original file-name + file-extension on the album view for each thumbnail.  At the moment I feel like taking a sledgehammer to Dolphin.

And don't mention cool iris, that thing was horrible, clunky to use.