deinterlacing in compressor

[Nick Meyers]

no worries, Paul.

and i guess that’s the answer to the original poster.

in the compressor de-interlace filter,
BLUR seems to be a BLEND of the fields.
looks great on text, crapy on a moving image.

as a compromise SHARP seems acceptable on text and the bg,
(but i’m only looking in the preview window)

nick

[Hector Berrebi]

Hi Rafael

since this thread seams to have been hijacked and the original poster is not around anymore 🙂 i would like to add a question

as i was thinking of how to write it, i threw out this small test. would like to know what you think.

source i worked with is PAL interlaced upper field, captured via decklink component, out of a mini DV source, to prores HQ, canvas window 100%,
Pic 1
seq set to upper. video monitor looks fine in playback, obviously not fine when paused. canvas looks comby on pause or playback on moving objects but sharp on edges. my test focuses on the entire frame and on the white pacifier rim

pic2
seq set to none, no combing but edges seam less sharp, video monitor slightly blurry, less sharpness on playback.

pic3
seq set to none, FCP de-interlace filter set to remove lower, looks better than pic 2 on the edges, but still not as sharp as original material. looks ok on playback. in video monitor, image is blurry and softer on playback and pause.

from the FCP manual “(de-interlace filter) Can be used to remove the upper (odd) or lower (even) field from an interlaced video clip. The remaining fields are interpolated to create a whole image, with marginal softening of the image as a result

obviously, FCP does not do that great of a job de-interlacing, but some sort of soft interpolation of one of the fields.

i tend to work more often with progressive material so i don’t encounter these problems on a daily base, but every once i a while they come up and annoy i will try the Nattress “Smart De-Interlace” too and see if it looks better.

any better way you know of in FCP? or did i miss a step and got it wrong?

i should probably try this with better source material too, however,
my though is that there is no way to get perfect results, and that there will always be some price to pay for de-interlace…

pic 4

this is the best i got out of compressor, setting the following, Prores HQ for interlaced material, video settings unchecked interlace,
frame control on, set to output progressive and better deinterlace mode i did try best mode first, it produced many artifacts (i even tried max anti alias) eventually, better mode got a better result than best

pacifier rim looks practically as sharp as original, but there are strange comb artifacts on the hand and around it, and it doesn’t look good in playback – more artifacts…

it seams compressor deals better with edges of static objects in the frame than with moving ones and FCP is the opposite.

any thought?

thanks

hector

Hector Berrebi
Schibber Group
prePost Consulting

[Rafael Amador]

[Nick Meyers] “in the compressor de-interlace filter,
BLUR seems to be a BLEND of the fields. “
If you want to de-interlace with Compressor, don’t use the default De-interlace filter.
It will yields less quality than when de-interlacing with the “Frame Control”.
rafael

http://www.nagavideo.com

[Rafael Amador]

Hi hector,
The issue when de-interlacing is not which field you eliminate, but how you rebuild the lost lines.
FC’s de-interlacer is probably one of the worst options.
RE-VISION FieldsKit is probably the most complete tool but in FC works only in 8b.
If you work with Proress, your only option (and the most recommendable) is Nattress plugins.

[Hector berrebi] “pic 4
this is the best i got out of compressor, setting the following, Prores HQ for interlaced material, video settings unchecked interlace,
frame control on, set to output progressive and better deinterlace mode i did try best mode first, it produced many artifacts (i even tried max anti alias) eventually, better mode got a better result than best “
The Compressor “Motion Adaptive’ filter (Better) is more or less the same than the Nattress “Smart De-interlace”. Only the picture areas with movement are de-interlaced. There is no point to de-interlace static objects. RE_VISION FieldsKit uses “Motion estimation” too.
The “Motion compensated” option (Best) I think that uses the “Optic Flow” technology. This can complicate things in fast moving areas of the picture creating artifacts.
Try nattress in FC and if you need something more powerful, try FieldKit in AE.
Hope this helps.
Cheers,
rafael

http://www.nagavideo.com

[Hector Berrebi]

helped 🙂

thanks rafael

Hector Berrebi
Schibber Group
prePost Consulting