Originally Posted by Kilian.ca
I don't recall ever having the impression of seeing fast forward motion in shop demos. Do other people really have that impression with frame interpolation? It still takes the same amount of time for an object to move from A to B on the screen whether frame interpolation is on or not.
Yes, but if the position of the object in the interpolated frame is not the same as what it would have been in reality, it's speed of movement from A to B will be wrong.
eg. a cartoon object moving at constant speed between A and B, if you wanted interpolation, and were going to add 1 interpolated frame it would be right to add the object half way between A and B.
But if an object started at A (eg. where it was stationary), then constantly accelerated to point B, then adding the interpolated object half way between point A and B would be wrong (since it would be moving too fast
to start with, then too slow
later on, compared to what it should have been).
Another thing is if people have been watching a lot of 24p content (without interpolation), when they see content (or that content) with higher frames/fields per second, it could seem wrong, even if it isn't - ie. even if that would be the motion that would be produced at the higher fps (though frame interpolation is mostly going to get it wrong - though I think, the more frames/fields that were analysed before generating an interpolated frame, the better it should be since it should better be able to determine whether an object was accelerating/decelerating/moving at constant speed etc. to better position the interpolated frame.
Is 'soap opera' effect entirely appropriate to describe frame interpolation?
No, it's just some people's way of trying to make this option, or higher fps in general, sound bad.
Though, like I said, there are problems with interpolation (and not just in the algorithms that decide where objects should be in the interpolated frame (where it's really impossible to know where the objects should be positioned in reality), but in how they make the interpolated frames, eg. they're basically warping/moving things from different frames together, trying to separate objects from the background, and even if the motion of objects was correct, you still can nd up with strange artefacts around the moving things in the frame, which is why real higher frame/field rates would be better, since it would be easy to skip frames for people who didn't like the more realistic motion, the higher motion resolution and the reduced judder). Though we could also do with better interpolation methods than are used in current TVs (eg. Phase Correlation? http://en.wikipedia.org/wiki/Televis...rds_conversion
or interpolation based on every pixel?).