Removing the upper field from an interlaced image

[David Bogie]

If you do that, there will be empty lines where the filed used to be.
Deinterlacing filters usually have setting that allow you to do chose a filed to make disappear. They usually eliminate one filed and then fill the empty lines with the other filed, though.

Tthe old standby was to create a solid of alternating alpha lines, one pixel high and one pixel apart. That was practical in the ol’ standard def days.

I hope you get better advice over the next few hours so have some patience.
I’ll be interested to see what comes up, too , from the wonks.

bogiesan

[Steve Roberts]

Hmm … why do you want to do this, and what do you want to end up with?

What will your desired no-upper-field movie look like?

[Curious Turtle]

Interested about the effect you’re after, but here goes:

Like bogiesan said, an alternating one pixel thin set of lines is the way to go. Personally, I like the Grid filter and have set up a Grid preset to act as a alpha track matte (or inverted alpha track matte if you want the other field).

Just make it a pixel wider than your comp width and set the anchor point x-dimension off screen. You can check out my ffx preset if you want.

All the best,
Ben

Curious Turtle Professional Video
Training | Editing |Support

[Richard Baguley]

Ben et al, thanks: I’ll try the line technique. What I am trying to do is to do more accurate tracking of an object in a video, but the interlacing interferes with the tracking. So, I am hoping that by just using one field, I can track more accurately. I am not going to use the video for anything but this track, so I don’t care about how it looks.

[Curious Turtle]

Well how about doing this instead:

Open up your comp settings and double the frame rate. So if you’re working at 25fps change the comp to 50, if 29.97 then up to 59.94 with you! And so on.

Good luck with your project,
Ben

[David Bogie]

You should have said so.

[Richard Baguley] “I’ll try the line technique. What I am trying to do is to do more accurate tracking of an object in a video, but the interlacing interferes with the tracking. So, I am hoping that by just using one field, I can track more accurately.”

All you have to do is double the frame rate of your comp. (Ah, I see Ben has already suggested it.) That makes every field a frame. There are many other ways to improve the accuracy of tracking. I think the online help system that takes you the web version of the manual has several links to tracking tutorials.

bogiesan