Does order matter for filters? If so, in what order do you guys put your filters?

[jellysandwich]

For example, let's say you had an anime show. You'd have to IVTC it, crop it, resize it, add a de-rainbow filter, de-noise it, and finally warpsharp it.

What order would you do this in?

js

[mg262]

Yes. In particular, put the inverse telecine before the resizing (probably put it first) or you will be in a real mess because the fields will be blended together.

As a general thumb, I would say that you should separate the filters into filters that reverse some particular effect that was not present in the "original" video:

Inverse telecine
derainbow
denoise

Apply these before the other filters, and try to apply them in the reverse order that you think the original effects happened. So if you think the noise happened before the rainbowing, apply the rainbow removal before the denoise. (In particular, that means that when working from VHS,before anything else you should remove any junk that you know was produced by your capture card.) After stripping out these "layers of distortion" to get as close to the original picture as possible, you can try things to change/improve the look, including cropping, resizing and warpsharp (I'll explain later why I don't consider warpsharp to be reversing an effect if you want).

That's the theory (from my point of view), and I have found it works reasonably well in practice, but it's always worth trying a few variants... and if you're not sure in a particular case, just try both variants and see which looks better. I would recommend stacking the two versions side-by-side and playing back in a media player as it is much easier to see the difference that way.(You will have to cut the width of each in half to do this... I wrote a small script to do that if you don't want to do it by hand; search for CompareVersions.)

[Leak]

Inverse telecine
derainbow
Just a minor nit: this might have to be swapped, depending on when the rainbows were introduced (before or after telecining)...

[mg262]

That wasn't meant to be a list in order... just a list ofthe filters that reversed some particular effect.

[jellysandwich]

Yes. In particular, put the inverse telecine before the resizing (probably put it first) or you will be in a real mess because the fields will be blended together.

As a general thumb, I would say that you should separate the filters into filters that reverse some particular effect that was not present in the "original" video:

Inverse telecine
derainbow
denoise

Apply these before the other filters, and try to apply them in the reverse order that you think the original effects happened. So if you think the noise happened before the rainbowing, apply the rainbow removal before the denoise. (In particular, that means that when working from VHS,before anything else you should remove any junk that you know was produced by your capture card.) After stripping out these "layers of distortion" to get as close to the original picture as possible, you can try things to change/improve the look, including cropping, resizing and warpsharp (I'll explain later why I don't consider warpsharp to be reversing an effect if you want).

That's the theory (from my point of view), and I have found it works reasonably well in practice, but it's always worth trying a few variants... and if you're not sure in a particular case, just try both variants and see which looks better. I would recommend stacking the two versions side-by-side and playing back in a media player as it is much easier to see the difference that way.(You will have to cut the width of each in half to do this... I wrote a small script to do that if you don't want to do it by hand; search for CompareVersions.)


Interesting, I never thought about it like that. Thanks, I'll keep that in mind from now on.

js

[Wilbert]

As a general thumb, I would say that you should separate the filters into filters that reverse some particular effect that was not present in the "original" video:

Inverse telecine
derainbow
You should derainbow first before doing ivtc. Filters like GuavaComb use the presence of a certain periodic behaviour of the chroma noise (which caused the rainbow effects). If you ivtc first, this periodic behaviour will be gone, and GuavaComb won't work properly.