[MysteryX]

This doesn't solve blocking at all. I'll need to run a separate filter for that. You're right, hand in the air on the right is better defined for KNLMeans. The biggest difference, however, is in the curtains and roof, where KNLMeans discards the subtle details as noise giving a slight plastic or washed out effect.

Note than in my sample, I'm applying upscaling and interpolation after denoising which amplifies the denoising difference. Small variations can however cause large variations in interpolation, explaining why one hand would be clearer while other objects have less details. Sometimes it simply changes the motion estimation so that the hand appears clearer one frame earlier or later. So we really have to look at the whole picture.