How to handle a fade applied to hard telecine?

[sirt]

Originally Posted by jmac698

My theory doesn't seem right. I looked at a subtracted fields. There does seem to be some pattern however.

Thanks for reflecting about this ! Anyway it is too complex for me, the only thing I can do is test and see what happens.

[mandarinka]

if it is regular enough, fft3dfilter could remove it if you supply a proper pattern image (the pattern mode).

[sirt]

Originally Posted by mandarinka

if it is regular enough, fft3dfilter could remove it if you supply a proper pattern image (the pattern mode).

Thanks, do you have a configuration suggestion ?

[Wilbert]

I don't see anything "blended" in this sample. The problem is that the fades were done after the telecine. I.e. those same-(24p)frame fields that are spread between two 30i frames have different brightness because of that, and don't fit together anymore.

I completely agree with Didee. You will have to undo the fading before ivtc-ing it (but i'm not sure whether this is possible to do in an acceptable way):

SeparateFields()
UnFade()
Weave()
Telecide(order=1, guide=1).Decimate(cycle=5)  #IVTC

[sirt]

Originally Posted by Wilbert

I completely agree with Didee. You will have to undo the fading before ivtc-ing it (but i'm not sure whether this is possible to do in an acceptable way):

SeparateFields()
UnFade()
Weave()
Telecide(order=1, guide=1).Decimate(cycle=5)  #IVTC

Thanks for your answer. What is that UnFade() ?

[Wilbert]

Thanks for your answer. What is that UnFade() ?

The opposite of fade, but sadly such a filter doesn't exist.

[Guest]

[bump after re-open]

[mirkosp]

I know it's meant to deal with moving text, but wouldn't ivtc_txt60mc get a perfect result anyway? A fade should hopefully be easy enough to interpolate with good results. That said, even if you don't get the fade back to linear it's not that big of a problem, it's going to look fine anyway in motion. So alternatively to ivtc_txt60mc, the simple solution is just to use vinverse (as it was already suggested) after you do proper ivtc (you most likely want to tell your matcher to avoid postprocessing the frames and perhaps you might have to manually make sure the matches are correct).
Hell, I'd say ivtc_txt60mc isn't really required to get back to linear. Ideally you could do this by doing a high quality bob, then just doing an overlay at 0.5 with the fields that need to be overlayed to get a linear fade.

[cretindesalpes]

On a 3:2 telecine pattern, vinverse() the 2-field image, and for the 3-field image, average the 1st and 3rd fields, match with the 2nd field and vinverse() the result to smooth the remaining combing. But sometimes vinverse() cannot cancel the combing, especially on oblique, thin and and highly contrasted lines (mostly with anime/cartoon sources). In this case you could replace vinverse() with daa(). You could also limit the changes by the difference between the average lumas of the two fields.

[sirt]

Originally Posted by mirkosp

I know it's meant to deal with moving text, but wouldn't ivtc_txt60mc get a perfect result anyway? A fade should hopefully be easy enough to interpolate with good results. That said, even if you don't get the fade back to linear it's not that big of a problem, it's going to look fine anyway in motion. So alternatively to ivtc_txt60mc, the simple solution is just to use vinverse (as it was already suggested) after you do proper ivtc (you most likely want to tell your matcher to avoid postprocessing the frames and perhaps you might have to manually make sure the matches are correct).
Hell, I'd say ivtc_txt60mc isn't really required to get back to linear. Ideally you could do this by doing a high quality bob, then just doing an overlay at 0.5 with the fields that need to be overlayed to get a linear fade.

Thanks for your help, I saved the filter as an AVS file but I don't know how to make it work. I've tested ivtc_txt60mc(23.976) on the iVTCed video but it doesn't work (invalid parameters) and with ivtc_txt60mc(24) it doesn't work as well because it doesn't appl on the frame I need.

Originally Posted by cretindesalpes

On a 3:2 telecine pattern, vinverse() the 2-field image, and for the 3-field image, average the 1st and 3rd fields, match with the 2nd field and vinverse() the result to smooth the remaining combing. But sometimes vinverse() cannot cancel the combing, especially on oblique, thin and and highly contrasted lines (mostly with anime/cartoon sources). In this case you could replace vinverse() with daa(). You could also limit the changes by the difference between the average lumas of the two fields.

Thanks, this is a comparison with daa() :









As you see the lines are solved but it looks like the video is also filtered, probably because it is an aliasing filter. But, at least, it seems to always work without needing to be adjusted (like vinverse). Do you maybe know something similar like this ? I think we are on the way !

[sirt]

Any idea ?

[GMJCZP]

sirt, try this version of daa() that I modified to make it more smooth.

# Anti-aliasing with contra-sharpening by Didée (thanks to Didée, modded for this case with nnedi3)
# Is required VerticalCleaner
function DAAMod(clip c)
{
nn = c.nnedi3(field=-2) #or use nnedi2
dbl = mt_average(selecteven(nn),selectodd(nn),U=3,V=3)
dblD = mt_makediff(c,dbl,U=3,V=3)
shrpD = mt_makediff(dbl,dbl.removegrain((width(c)>1100) ? 20 : 14),U=3,V=3).verticalcleaner(mode=2)
DD = shrpD.repair(dblD,9)
return dbl.mt_adddiff(DD,U=3,V=3)
}

[feisty2]

@sirt
got an accurate solution for this issue.
but you'll have to switch to vaporsynth to test it cuz I don't do avisynth plugins