Can I scroll text atop an image that I chose?

[misha]

does anyone know how to make texts scroll on top of a picture that you chose
and set as the background of the slide? the "credits" option only works if
the background was chosen from one of the "slide design" options.

 

[Luc]

Misha,
There should be no problem with your own picture.
See here for a thorough explanation of the credits effect and how to use it.
http://www.rdpslides.com/pptfaq/FAQ00207.htm
Luc