list of application variables for Gallery 1?

The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Gallery URL (optional but very useful):
Gallery version: 1.5.3
Apache version: 1.3
PHP version (don't just say PHP 4, please): 5.1.3
Graphics Toolkit: NetPBM
Operating system: Redhat Enterprise Linux
Web browser/version (if applicable):

I'm looking for a list of variables as pertains to the particular image being handled at the time, by view_photo.php or in view_album.php at each thumbnail iteration.

Mostly I just need the file name of the image without the path.

Any help is appreciated.