Where is the alt text printing located

Hi,
I want to change the alt text location for my thumbnails.
Using printLatestImages() , the alt text is the same as the title but I want to change it, Iooked up a really old thread:

http://forum.zenphoto.org/discussion/1719/changing-alt-text-for-images

I looked through template function but I cannot find where:

alt="<?php echo getImageTitle(); ?>"

is located. The documentation did not help much, anyone know where that line of code is located?