You can adjust the size of the PDF which will improve the image quality in the Web Portal > Forms > View form template > Edit > PDF, make changes as per image below;

The photo quality can also be increased in the App. We suggest that the Photo Quality be adjusted to 80 as optimal, Photo Width be adjusted to 960 and the Photo Height be adjusted to 720. However, you are able to adjust the photo settings based on your requirements.

To do this in the App > Settings > Photos > Make the necessary adjustments.