yes / maybe. I would be happy to help with this. I'm GM'ing a game today though so I will check back later. What is your map (original file)? From your computer, or from Marketplace of Roll20? What zoom level are you seeing it blurry? Generally the answer is have a higher-resolution map JPG, and, don't over-stretch it beyond its original resolution on the tabletop. This is not a hard-fast rule, it can change depending on a lot of graphic quality factors, so let's take a look at your specific map and page settings.