if you want to show the file name on the page, you can add it next to the hidden field:
<input type="hidden" value="<?php echo $row_WADAsliders['background']; ?>"><?php echo $row_WADAsliders['background']; ?>
or you could even display the image by adding a img tag:
<input type="hidden" value="<?php echo $row_WADAsliders['background']; ?>"><br />
<img src="path/to/images/<?php echo $row_WADAsliders['background']; ?>" width="200" height="200" />