[MPlayer-dev-eng] design for motion-adaptive deinterlacer

[Arpi]

Hi,

> I've been thinking about writing a good motion-adaptive deinterlacer,
> since they all seem to suck. So I'm sending a few ideas to the list

hmm, my favourite topic :)

btw, it should be a combined temporal denoise & deinterlace filter.

> 1. Identify areas of motion.
> 
> Using a simple difference threshold pixel-by-pixel is no good. If the
> threshold is too low you'll get tons of motion from temporal noise,
> while if it's too high, you'll miss slow changes in the low frequency
> components which cause very ugly noticable combing (think of gradual
> change in light level).

I've made some weighted group of pixels, in my g2 filter "madei"
(see video/vf_madei.c).
it works quite well, but i think your idea with freq-space weighening
is better.

> 7. Apply motion compensation to bring the fields in line.
> 
> Deform the older field so that it mostly matches with the newer field,
> using the motion vectors/transformations from step 6.

hmm, this is the most difficult part.
if you can't do it right, strange effects will happen.
when i wanted to buy a new TV, and tested a few models, i've found a
samsung one (dont remember the model no, it was a quite big, 16:9 100hz one)
which did motion compensation, but sometimes it was buggy, and small
patches of the image moved to wrong direction. it was quite funny :)


A'rpi / MPlayer, Astral & ESP-team

--
PyMaViS - my answer to worm storm - http://mplayerhq.hu/~arpi/pymavis/