Converting pdf to jpg in multiple directories?

Hi!

On my Ubuntu I have thousands of files in a couple hundred directories. I'm trying to convert the pdf's to jpg's.

I used this command in terminal:
for fname in *.pdf; do convert $fname ${fname%.pdf}.jpg; done

It works great but the problem is I have to run this in terminal for each folder/directory so it's time consuming.

Is it possible to covert all the pdf's in the sub directories from the root directory at once in terminal?

Thanks for your help