I have this option on my LGPK350 50 inch TV and do find some times for grainy looking films really helps take it out and makes the picture better.
Some people don't like it when they and DNR to Blu Rays.
I think it should not be added to films and let people chose to turn it on if they have the option on the TV.
What do you think about this?

The general rule is, it's best to turn off the digital enhancements on a TV. I've always found that turning them off improved the picture, so that's how I have it set up now.......I would suggest that you try with and without and see what you prefer on your particular set.

I suppose it is down to how 'offensive' or distracting one finds grain. Some people like a really gritty look while others prefer a smooth look. I don't think moden TV's show grain very well though - it ends up like a swirling mess.

Like call100 I also have turned off all the digital enhancements on the TV, and on the 3D Blu-ray player as well. When I reluctantly set up TVs in one of our local sheltered homes, I try to go through the settings to show the difference, but most of the time the folks there can't be bothered, and that's OK with me, it's their TV. I just wish the damned things weren't so complicated, the seniors can't figure out the menu systems at all (and sometimes I can't either).

Same here. The first thing I do when getting a new tv or home cinema is turn off all audio/video enhancements. I found on my Samsung tv and cinema, that most where set to on or auto straight out the box.

bluray is a very faithful image to the source, you can assume that if the studio wanted to remove some noise they would have done it already, professionally and better than your tv. so if you do apply a filter to bluray you are basically instagramming it, changing the way it looks to one you prefer. which is fine, you just need to know that.

it's more useful for reducing encoding artefacts on lower bandwidth material. you don't tend to get much temporal noise, but a wouldn't be opposed to a bit of spectral filtering on for example, freeview.

If its anything like NR in digital photography you will lose detail as well as noise, its a compromise, me personally I prefer detail and a bit of noise rather than smoothed over pixels.

there are some quite sophisticated NR techniques, what you say is probably true, but in video it's slightly different...

...because of the time element you can use temporal techniques. that is to say if for example you have low light noise you can compare one frame to the previous and the next and say that spec shouldn't have been there, but that piece of fine detail should. you can apply global motion compensation algorithms to accurately compare frames when the camera is moving too.