Hello,
How do I add additional extensions to zenphoto?
Which file to edit?

I mean the type extensions .png,.psd,.awf, etc. ??
HELP !

Zenphoto uses server based graphic libaries, GD or Imagick. It supports what thoes provide. However Zenphoto is mean for websites so it by default supports web formats (png should really be no issue).

If you need other formats you need to write a plugin. See the plugins class-Anyfile, class-textobject or class-Webdocs for a guide how to do this. By any means they might not work as normal images and you might not be able to let Zenphoto create thumbnails and such.