Unsharp mask VirtualDub filter question

[Xoanon]

On the above filter, when applying it there is a checkbox for "interlaced video", which you tick if you're using interlaced video. I am applying this filter after using the Deinterlace filter on the "unfold" setting. When I unfold fields, is the video still classed as being interlaced, and therefore do i check "interlaced video" on the filter or not?

In fact, why unfold fields and then refold them in the first place?

Thanks guys as always!

[adam]

You have to unfold (I call it split) fields before you resize interlaced footage otherwise the fields get out of order and basically scan lines don't match up with their surroundings. In other words, the image get garbled.

As long as your fold filter comes after the unsharp filter, then you should NOT check the interlaced video option. Vdub processes filters in the order you add them.

[Xoanon]

Right, well Im not resizing the image; just applying some niose reduction filters, etc. Is there any need for me to unfold fields in that case?

So just to confirm, I make sure the interlaced option is OFF if it comes before the refold option.

[adam]

I don't think there is any need to unfold if you aren't resizing, no. If you do unfold then just treat them like progressive until you fold them again, so yeah if you use unsharp before fold than you would turn the interlaced option off.

[Xoanon]

Doesnt unfolding make things like (noise reduction) filters more accurate? Like, as opposed to working on a folded image, the filters can work on separate fields?

[jagabo]

If you're doing any spacial filtering (with filters that don't have an interlaced mode) then you have to unfold first. Otherwise the two fields will bleed into each other.

[mikiem]

IF it helps...

Most filters, if they are not looking for field differences over time, will work to the extent that you get output, regardless the source video. Meaning, if in doubt, do a test render and see what you get. I've predicted one thing often enough, and been wrong.

Sometimes you get unintended consequences, maybe even normally bad stuff, that works to the advantage of a particular video. Sometimes it doesn't work as well as intended, especially on other scenes later in the vid. Either way I'm personally of the opinion giving stuff a try is a good thing -- probably since I started working with graphics before video. :P