Anthracnose vs Cercospora

It seems these two diseases are used interchangeably on many rose sites. Can anyone tell me the difference between these two?

This cercospora…

http://www.aaes.auburn.edu/comm/pubs/circulars/circular329.pdf

…sure looks a lot like this anthracnose:

Thanks!

Shane

Also, does anyone know if different conditions contribute to the formation of these? I cannot find much information on either of these.

I never really cared which one was affecting my roses, but my curiosity has gotten the best of me. One of these is defoliating my William Baffin.