Best rotoscoping settings for low res footage with lots of motion

[beahaxby]

After effects 2023

Mac OS

Sonoma 14.1.2

Apple m2 pro chip

16gb memory

I need to rotoscope pixelated footage of a running body for a piece of health club advertising.

There are loads of settings in rotoscoping that I don't understand that I could fiddle with imperfectly, but I would rather just show the footage and what I'm doing and you can perhaps tell me what settings I should adjust (propagation/base refine edge matte etc) and how.

I can't reshoot/improve the footage because the footage is taken from a. low-resolution medical camera not a videograpers camera.

Towards the beginning of this video you can see the video I'm working with, and towards the end you can see it in the context of the whole composition its going to be in.

Thanks ever so much

[Rick Gerard]

You first want to add some color correction to the footage to improve the edge detail and contrast between the foreground and background. Don't try and get the final color correction. Crank on the controls until you have better edge detail, and contrast. You can even add some hand masking if it helps. Next, pre-compose the footage, moving all attributes and adjusting the pre-comp to the layer length. Then, use the Layer/Open menu and try running Rotobrush. If successful, you can turn off the color correction in the Pre-comp and the masks. If it takes longer than a few minutes to generate a good Rotobrush, it is advisable to pre-compose the Rotobrushed layer again, then use the Composition/Pre-render menu to render and replace the Rotobrushed layer with footage that has the alpha channel.

If you cannot generate a good matte using Rotobrush, the other option would be to use Mocha AE on the Pre-composed/Color-corrected footage and generate your mattes there. Mocha AE is a lot easier to use than manually editing a mask. No matter what workflow you use, make sure you don't spend time rotoscoping any frames or details you don't need to fiddle with in the final comp.

I hope this helps. 

[beahaxby]

Hey Rick

Thanks for your answer. The footage I'm trying to track is the grey one at the beginning so I can't colour correct it. Is it possible you're thinking of the footage shown at the end? That's in the main composition, I'm not trying to track that (have explained the composition below)

Drawing from what you've said though, it sounds like what youre saying is that before I need to try rotobrush, I should exaggerate the form of the thing I'm trying to track through masks and contrast manipulation. I can imagine making a really rough mask that follows the movement of the legs and using that mask to create a 'spotlight' on the legs, then precomposing that and then rotobrushing that?

The organisation of the project is so:

• Main composition where everything is (seen at end of video in last post) has live action colour footage of actor standing walking and running on treadmill. It has callouts of spine, feet, hips and lower body (footage from the medical technology cameras) which are going to be tracked according to the motion of his body. These callouts are sub compositions in the main composition described below. 

• Call-out compositions (seen at the beginning of the video in last post) these are different shaped callouts that let you drag and drop images and videos into them.  `3/4 have white backgrounds, and so I want to rotoscope the pixelated 'lower body' footage you see at the beginning so its also against a white background.

• Image/video placeholders inside call-out compositions This is where you drag and drop your footage into, and where the problem layer of the low quality footage is.

 

[Rick Gerard]

What does the gray blobby footage look like? Is the first frame the gray blobby thing, or the first couple of seconds after that where Rotobrush is failing? I'm still not sure what you are trying to track.  If I could see the actual clip, I might be able to give you some better suggestions. 

If it is the footage from 1 to about 6 seconds in your YouTube video, you're still going to have to run some temporary color correction on it to get Rotobrush or even Mocha AE to have a chance of tracking it. Something like this:

I think Mocha AE will be a better choice to roto the footage. It's going to take some keyframes. After you get the mattes made, open the Pre-comp and remove the color correnction.

Boris FX Training

[beahaxby]

Hey, really appreciate the reply, yes thats the right footage. Do you mind sharing the video attached at a higher res, maybe uploading to google drive or youtube? I can't see properly here

[Rick Gerard]

I just took a screen capture of your YouTube footage and added a Curve adjustment, then pre-composed. I just posted a GIF