antialiasing the jaggies
by Matthew Beall
on
May 1, 2008 at 6:07:46 pm
I have a scene of a large kitchen where the camera pans across it.. There are lots of nearly-horizontal lines that are fairly contrasty.. The scene was shot on film and transferred to video with telecine.. There is horrible aliasing on the lines.. I can remove the telecine and look at it 24p on my monitor and it looks OK.. But once we put it in the timeline and render it for DVD, it looks horrible..
Any way to smooth the jaggies, yet keep the overall scene sharp?
Re: antialiasing the jaggies by Dean DeCarlo on May 3, 2008 at 3:49:45 am
If the footage looks ok as progressive then it sounds like a fielding problem. What are you using to create the DVD? If you are working in NTSC - SD then your footage is being scaled or cropped from 720x486 to 720x480. If it isn't done properly then the fields are not going to be in the right place and your picture will look like crap. I avoid scaling to make dvds and crop 2 lines off the bottom and 4 off the top. If you do 3 and 3 then the footage will be shifted up one field and the dominance will be wrong. Hope this helps.
Re: antialiasing the jaggies by Matthew Beall on May 6, 2008 at 4:31:27 pm
I avoid scaling to make dvds and crop 2 lines off the bottom and 4 off the top. If you do 3 and 3 then the footage will be shifted up one field and the dominance will be wrong.
Ahh, that is good info.. I have a 720x480 composite, and just load the footage without moving/shiftin/scaling/cropping.. This gives me 3 lines above and below out of frame.. So I should move the footage up 1 line? That will give me 4 lines above and 2 below, right?
Re: antialiasing the jaggies by Dean DeCarlo on May 6, 2008 at 4:38:24 pm
Yeah, you can do any combo that looks ok as long as you shift in pairs and not odd numbers. I'm pretty sure that's right. you could move 6 up or down or 2 up and 4 down or 4 up and 2 down etc. There should be options to do this stuff in your DVD mastering software also but you'll have more control in Combustion. I've discovered this purely by knowing something about fields and trial and error. Considering there is an incredibly annoying 6 line difference between broadcast and DVD there is surprisingly little documentation on it and the DVD programs I've used do not seem to automagically handle it. Good luck with it!
