Image resolution being downscaled

Is there a trick to getting uploaded images to retain their resolution quality? Both images I've upload and premium assets I've bought from the marketplace both end up appearing way less sharp than their original pngs.

It could be an issue regarding display size vs native size. Roll20 re-renders all images at a variety of sizes for faster display at different zoom levels. Depending on the nature of the image, this can result in unexpected display. Another possibility is that extremely large images may resolve in stages, also a performance consideration (i.e. they may take some time to become sharp.)