How to change logo image in header.php in all but Home page

Hello,
I am trying to figure out how I can have my logo image file appear as a different image file on all of my pages and post pages except for my home page.

I am working on this project for school so any help would be greatly appreciated! The site is here.

I want the “Hi there” image that appears at the top of each page to be a smaller version of the Nik Designs logo on every other page but the home page. The logo is actually named “slogan” and the hi there is “logo” currently.

Here is the code. I was thinking that I could do this using the conditional is_page (), but I am just not really sure how to do it.

Please help, I would really appreciate it!

Thanks!
Nicole