Jagged edges when using Pan & Zoom

sittingduck · Post by **sittingduck** » Tue Aug 19, 2008 6:08 pm

I have created a video sequence using the Pan & Zoom filter. It's a sequence of a person running in front of a windmill and I really like the sequence and would like to keep it. However, the Pan & Zoom filter has also resulted in an unwanted sideeffect: The runner and the moving wings of the windmill are jagged which is not pleasant to look at. I'm guessing it has something to do with deinterlacing, but thought it would be the wisest to ask ones in the know. Searching the forum didn't turn up anything as it seems this filter is mostly used for still images. The footage is DV shot in 16:9 (which is a no-no, I have learned...) on a very cheap DV camcorder. I know using a filter such as Pan & Zoom degrades the image because it lowers the resolution, but that is not an issue for me. It's just the jagged edges, that are bothering me. Is there any way to clean up the image? Thanks in advance.

troppo · Post by **troppo** » Wed Aug 20, 2008 1:57 am

There's nothing wrong with DV shot in 16:9, in fact the government owned TV channel I shoot for prefer this format. I think the problem with 16:9 on older cameras was that they just added black bars to the top and bottom effectively cropping the recorded image. New DV cams don't do this, they shoot in anamorphic (squeezing 16:9 into a 4:3 frame size).

Anyway, about your question, yes it most certainly has something to do with field order. Try swapping it or deinterlacing. I assume it's captured as DV lower field first?

I would even render out a short section of it to see if the jagged edges are preview only artifacts.

sittingduck · Post by **sittingduck** » Wed Aug 20, 2008 12:22 pm

When looking at the media source options all my clips are lower field, yes.
Troppo, thank you so much for your suggestions. I tried rendering the sequence in every possible combination of lower field, upper field and framebased with the deinterlace and flicker reduction options. Framebased flicker reduction actually gave an acceptable result and looks alright when played on both my pc and on my tv. Are there any downsides to doing this, considering the rest of the timeline is regular lower field?

sjj1805 · Post by **sjj1805** » Wed Aug 20, 2008 1:44 pm

If it looks right it is right.

An alternative to the pan and zoom filter is use the copping filter - make sure you untick the fill color box.

Sometimes it is worth experimenting and bending a few of the rules.

sittingduck · Post by **sittingduck** » Wed Aug 20, 2008 2:54 pm

Thanks again. I will toy around with the cropping filter also.

troppo · Post by **troppo** » Thu Aug 21, 2008 2:27 am

I use the moving path instead of the pan & zoom filter most of the time, using the boundaries of the TV screen to do the cropping.