Approach to Removing Stuff with AE

Mark Harris

Mark Harris

Pain in the ass
So I just shot some scenes for a comedy I'm working on. We were very happy with the lighting, and the camera work. But in a number of shots, China balls can be seen reflected in picture frames. Now, had we be thinking a little harder, we could have powdered those frames or something. But...

So I am using this as a chance to beef up my AE skills and wanted to run the basic approach by the gurus here to see that it's sane.

The footage is all shot docu style, so the camera is EVERYWHERE and ALWAYS moving. So my plan is this:

Frame by frame:
Here is a grab of the first test: http://www.desperatecomfort.com/working/mh_5/roto_after.jpg

Here's how:

Layer top: A solid the same color as the picture frame matte, with a matte cut to the shape around the painting.

Layer middle: The original footage with a matte picking out just a chunk of the painting, and then doctored with the clone stamp tool. The artist is probably rolling over in his grave - if he's dead.

Layer bottom: orginal footage: http://www.desperatecomfort.com/working/mh_5/roto_before.jpg

My plan is to go frame by frame in the shots and basically keyframe those masks as necessary. I don't see any other way.

Am I a crazy man?
 
This happens all the time. This is what you do:
Create a clean plate of the offender, in this case the frame, then track the camera move and apply the move to the clean plate. In this case using a 4 point tracking should work very well.
 
that's cool, thanks for the advice. I don't have access to a clean plate of that, but you gave me the idea of taking a grab and creating one in Photoshop say, and then tracking that. At least that eliminates one matte and simplifies the process a little.
 
Mark, I've been in a similar situation and I still deal with general cleanup in AfterEffects for a feature that I shot recently. As with everything, the speed of work depends on the quality of your tools. When doing extensive touch-p of footage a good rotoscoping tool can literally save you hours and hours of work. I use Silhouette Roto almost every day and I can't mention that program often enough. Take a look at it at http://www.silihouttefx.com
Also, if you use Silhouette Roto you can gain a lot of speed in your paint/roto work by using a Wacom tablet. These two tools together are a killer combo.
One of the true gems of Silhouette Roto is that you can use it to track shots based on the keyframed shape of the mask that you created. The tracker can then be exported to AE and ntegrated with the other effects for blurring/cloning etc.

--
Paolo
http://www.2nd-unit.tv
http://www.digitalcinemaexchange.com/forums
 
Last edited:
graymachine said:
Actually, I just posted a similar tutorial on this. It but be a little on the "simple" side compared to what you need to do, but I thought I'd mention it.

http://www.graymachine.com/tutorials/track.html
Click to expand...



Nice tutorial!



Mark, rather than use the clone stamp in AE, you may wanna think about extracting one frame of video and repairing it in Photoshop and then using that repaired portion tracked in AE. I've run into that kind of problem more times than I can remember, and with a stationary camera, or one that has nice smooth moves, AE's clone tool can be effective, but I've found that rebuilding the part of the frame in question and then applying track data to it works better. You have finer repairing tools in Photoshop, and that helps. If your lighting is nice and balanced, and camera movement is restricted to less than around 110 degrees of pan, you don't even have to worry about the element losing it's gamma. Even if there is noticable Luminance shift through the shot, all you need in 90% of the cases is putting Levels on the element, and keyframing slight gamma tweaks.

As graymachine pointed out in his tutorial, I would look for the part of that shot that has the most of the picture in it, and then rebuild it, and apply track data. You will probably need position and rotation data, as well as probably enabling motion blur.


corner.jpg



Right is AE, Left is Photoshop.
 
yeah, I am going with taking a frame grab now, and doctoring that in Photoshop and then tracking with it.

Thanks for the tips, guys! I am roto-ing my pants off this weekend, so will post something when it's ready!!!
 
Well, here is my first pass at this. It's only two seconds. And it's going to be wildly tricky, because after this two seconds, the zoom changes such. And there are some flaws in this one, I am aware.

I need to go back and read up how to make the tracker more fine-grained. I used it, but wound up moving a bunch of keyframes by hand. Also, I did not spend a lot of time on the photoshop part as I wanted to get on with the compositing.

Anyway, enjoy and leave some feedback. And for the love of God, someone find me an intern!

http://www.desperatecomfort.com/working/mh_5/downy_comp_test.mov
 
Hey Mark, starting to look good... Make sure you remove the pulldown before you start tracking, not sure if you are doing that already, but it sems that your track could be a bit tighter. If you have a zoom make sure you have both size and rotation on.
 
Looks great Mark. I'd say if you hadn't said anything, I never in a thousand tries wouldve guessed that it was roto'd. The shots could use a bit of CC though :)
 
thanks man, that's good to hear. I put up the 720 so people could scrutinize it full size.

And for CC, yeah, that file is raw out of the camera otherwise. And I don't even know if that shot will end up in the film. I wanted to work out the techniques first.
 
I didn't see a way to download a trial. can you give me any general idea of how it works and what it does to make life so much easier?
 
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