De-Interlacing What are the best methods?

What I have done in the past is in After Effects do a gaussian blur of 1 pixel vertically to de interlace my footage. I am not happy with that however. It tends to leave very pixelated edges and it obviously still looks like there are two seperate images.

The reduce interlace flicker filter in After Effects seems to do the same exact thing as a vertical blur.

When dealing with still frames in Photoshop, I use the Video>DeInterlace filter. This tends to successfully get rid of the "double image" and the edges seem less pixelated. There is no such filter in After Effects, however.

When I interpret my footage as I import in AE I always leave seperate fields to OFF. I have been experimenting with upper field first and lower field first, and it does get rid of the "double image." The edges are still pixellated, but it may not be as much as the gaussian blur.

I checked the box for motion detect and it did not seem to change anything. What I really don't have a clue about is the Remove Pulldown choices. They are:
WSSWW
SSWWW
SWWWS
WWWSS
WWSSW
and then there is the button for Guess 3:2 pulldown

Can someone tell me what these pulldowns mean?

And the main question in this post:
What is the best method for deinterlacing?(specifically in After Effects)

 

Turn separate fields on. Lower field first for NTSC. That's the best way to deinterlace in AE and will give the same result as the deinterlace plugin in Photoshop.

A 3:2 pulldown is the method by which 24 fps film is transferred to 29.97 NTSC video.

Basically, in an 3:2 pulldown, one frame of film is broken into three fields of video, and the following broken into two, and it alternates, placing the fields in order to fill out the video signal. So if (as they do in AE) we represent the three-field frames as W, and the two-field frames as S, we get the following conversion:

W,W | W,S | S,W | W,W | S,S |

Where four frames of film have filled five frames of video, making one second of film last one second on video.

If you're working with a clip from a pulled-down film, the pulldown for your clip may not start as outlined above, but may be any of the available combinations they give you to pick from in removing the pulldown.

Your video has no pulldown, so don't worry about it.

M. Scott

 

So in the frame that is seperated into three fields is it that the top most horizontal row of pixels is in the first field, then the second row in the second, then the third row in the third field?

Then for the second frame that is seperated into two fields it is the first horizontal row of pixels in the first field and the second row in the second field?

If that is so, wouldn't some frames have horizontal rows that are not filled with any image at all?

For example, WS would have the top row from the first frame, then the second row from the second frame, and then the next row would have nothing?

Am I not understanding this correctly?
Perhaps a visual would clear it up for me.

 

Although this page deals with progressive scan DVD players, the gray box at the does a good job talking about pulldown, and de-interlacing of regular video footage. (Including some nice visuals)

If you still have questions after reading it, feel free to ask them here.
Clickie.

 

Can anybody tell me how to de-interlace footage in Premiere?

 

To deinterlace in Premiere (which is what I do) when you export your movie and the settings box comes up. Go to the last setting box (special features (I think) this is where you can crop out of Premiere as well). There is a small box to check to deinterlace the footage as it makes the movie.

 

NXTB: What a BRILLIANT page on explaning pulldown.

I do not agree with one thing though... it talks about "feathering" and "combing" as "flaws of interlaced video"... but you never actually *see* that "in real life" because the two fields are displayed *offset in time*. Yes you DO see it if you pause the frame, view it on a computer, e.t.c.... but in a shot of an actually moving object you dont really "see" the "combing" because it is part of the motion... you "see" a 60 fps motion.

(Unless you sit on top of the TV w. a magnifying glass in nitpick mode eating speed.)

/Z

 

I agree Zap, but I get the feeling that these guys are trying to reproduce the film as accurately as is reasonably possible. Keep in mind that this page is really an introduction to a series of reviews they conduct on progressive scan DVD players. It's meant to show the benefits of such a system. (Explain to someone why they're paying that much more)

"Unless you sit on top of the TV w. a magnifying glass in nitpick mode eating speed."
-- Some of these videophiles might do just that!


It is a great link though and I suggest the rest of you still confused on this topic check it out.

 

Well the only time you would "see" the combing is when the image is still (not part of its proper image sequence) and displayed *progressively*

I assume these people are talking about progressive TV's? Well of course an interlaced frame displayed on a progressive TV will look like that, just as it does on your computer.... but.... alas, I digress.

What does confuse me, though, is this: I have a 100 HZ TV (PAL). Now I wonder, how the heck does that work, really? Because the interlace still works "as it should". Now how on earth can it display the image 100 times instead of 50 times and get it right? Anybody have any info on how the 100HZ tv's work? Does it simply do 1st field twice then 2nd field twice and thats it? Or something more spooky?



Btw, for the original question, the proper answer to "What is the best way to de-interlace" is "Dont - buy a progressive camera. I have a Canon MV30i (known as "Optura Pi" in the US) and it works just fine, true progressive image with perdy damned nice quality although it's only 1 CCD".

/Z

 

They are indeed talking about a progressive TV. An interlaced TV wouldn't benefit at all from a progressive player.

As for the 100hz... that's spooky either way. I would assume it's just to reduce flicker or eyestrain... we don't seem to have that problem in the US with 60hz. I too would be interested to hear if they do something other than display the same interlaced field twice (This is what i'm assuming they do).