This is an example of Video Artifact Premium color and film grain filters. The original video is 1920x1080 50p AVCHD MTS file from Sony HX20. Because a lack of bitrate there is no small details. It is very hard to improve it, so I used a film grain to add a texture sense.
Horizont Grain, 1x crop.
Resolution is improved, 1x crop.
Before / After