Participating Frequently

Question

Any alternative method to Rotobrush to cut out a person from a video and use it in Premiere Pro?

Forum|Forum|3 years ago
June 21, 2022
3 replies
3637 views

I am a beginner in After Effects and I thought that Rotobrush 2.0 is the easy solution I see dozens of people cheer about in YouTube...

It's killing my project currently, spending 4 hours to do a very mediocre result and then crushing.

The footage is a bit challenging, 360 video, 7680x3840, 29.97fps. but the lenght is only 16-20sec.

I need to cut out individual people from the video so I can use them on top of another video in Premiere Pro (with transparency). I managed to do one figure which took 4-5 hours and it's badly done.

Propagating the frames takes hours, to go back and correct the outline of frames is impossible and freezing takes hours again. Second time I tried crushed my computer:

AMD Ryzen 9 5900HX with Radeon Graphics

32.0 GB

Windows 11 Home

After Effects 22.4

I've also tried on Macbook pro, 2.3GHz, 16GB RAM, AMD Raden Pro 5500 8GB.

Running Catalina, 10.15.7

After Effects16.0.1

Here the lagging is almost the same, although it's much older system.

I've spent too much time on this. The figures in the video are mostly standing and move very little.

My question is: Is there another method to do what I need in Premiere Pro without using this Rotobrush? Would you do that with object tracking in Premiere Pro? How do you do the transparency? All of the tutorials I find is for removing object...

Any help appreciated.

This topic has been closed for replies.

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Rick Gerard

Community Expert

If you do not plan a shot and shoot it with visual effects in mind, you are asking for trouble. The choice of costume, lighting, background colors, background action, and shutter speed (Rotobrush hates motion blur - I shoot footage that is going to need to use that tool at a minimum of 1/200 of a second - you can put the motion blur back in after the mask is created), all make a difference.

I have had 7 or 8-second 4K shots that I could successfully use a combination of color correction, animated masks, and Procedural Mattes (using color channels to generate transparency). The shot is then pre-composed, and Rotobrush is used to finalize the matte and clean up some of the edges. The whole shot can usually be finished in a few hours.

Suppose the shot is incompatible with any combination of those workflows to simplify and speed up the Rotobrush operation. In that case, you could easily spend a couple of days on a single 7-second shot and still have a few frames with some significant problems.

We could probably make some more meaningful suggestions if you could embed* a screenshot so we can see what you are dealing with. No matter how good the AI is, a computer can't tell the difference between the blue pixels on a moving shirt sleeve and the blue pixels on a car in the background, especially if the arm is moving and has some motion blur. It's little details like that that can take days to clean up.

I hope this helps a bit and it is not too discouraging.

* The "Drag & Drop here..." area works, but it is a pain for the forum users to access the photos. You can use the toolbar, drag your pictures to the reply field, or even copy and paste the file directly in the reply field, then size them up so we can easily see them.

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Niya245332451q2eAuthor

Participating Frequently

Here is a frame (chopped head for privacy issues). Thank you Rick, unfortunately the footage is exactly the opposite of what you describe! Black clothes on black background, yellow laminate and yellow/red brick wall very close to skin tone of people etc. I guess this is a rotobrush disaster scenario.

I used Mocha as you suggested and achieved acceptable results in relatively fast process.

Lesson learned.

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Rick Gerard

Community Expert

I would probably have used Mocha to roto just the black pants, then used Rotobrush to create a matte for the rest of the body. If the shot is more than a couple of seconds, I would probably split it into sections where one combination of tools would work better than another.

Glad you got it figured out.

Roland Kahlenberg

Legend

Rotobrush works well but its accuracy depends on the footage with specifics to the object's boundary to the rest of the footage - Rotobrush prefers the boundary to be distinct in terms of colors/luminance and less movement, the better. You can also combine Rotobrush with standard masking tools. And for old-school, professional workflow, you can use Mocha to do the rotoscoping.
Perhaps you can do a revisit to give it another go when you have more time to dig in. OH! And the shorter the footage, the better too. Long footage will require a more performant system for a more efficient and effective interactive work.

Very Advanced After Effects Training | Adaptive & Responsive Toolkits | Intelligent Design Assets (IDAs) | MoGraph Design System DEV

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Niya245332451q2eAuthor

Participating Frequently

Yes I used Mocha and it was fast with OK results. Thank you.

Peru Bob

Community Expert

You can try masking in Premiere Pro, but AE has better tools for that than Premiere Pro. Rotobrushing is a time consuming job and requires a lot of skill and patience.