This is an upscale from 720p to 4k using Topaz Labs wonderful Video Enhance AI software. Note how aside from the awesome 300% upscaling, that the noise in the render is highly suppressed, without losing too much of the details. In fact, in most areas, the definition is improved and sharpened.
This software really helped with a recent project, upscaling over 7000 frames of rendered CG on a tight deadline, to a format and level of quality that would have taken many weeks if rendered at full output size and quality settings.
Note: This is not a paid promotion of this software. I just wanted to share an example of how great a job it does!