<p>This isn't chroma keying. If your subject isn't in front of a green screen (or blue) then you're only other alternative is to mask it, rotoscope to be precise. After Effects does have a tool called a rotobrush that let's you brush around the edges of your subject but it's not the most precise or clean mask.It will however make for a very quick rotoscope. If you go frame by frame, you can make a mask with the pen tool and key the shape each frame as you adjust it. 72 frames at 24 frames per second would give you three seconds like you're estimating. That's about 2 days of work for someone with a decent amount of experience with the pen tool. Hope this helps.</p>

CC BY-SA 3.0
2017-04-08T14:03:58.520Z
How long it takes also depends on what the footage is. Static shots of a bald guy meditating or handheld footage of a hair metal band crowd surfing at a concert?
stib
CC BY-SA 3.0
2017-04-08T04:28:17.300Z
2017-04-08T04:28:17.300Z
LetTheWritersWrite
<p>I'm not sure if this should be for photo or video, but let's say I see a part of a video that I would like to add a green background to, like chroma key, but the background isn't a solid color. Could I be able to select only the parts that I want to keep, and do this frame by frame? What I'm doing will only be about 3 seconds long. Is this possible with a program like After Effects, or some kind of Adobe program?</p>

<after-effects><chromakey>
How can I take a part of a video and chroma key only the parts that I select?
ToastHouse
# How can I take a part of a video and chroma key only the parts that I select?

(Asked by: username_0 on 2017-04-08)

I'm not sure if this should be for photo or video, but let's say I see a part of a video that I would like to add a green background to, like chroma key, but the background isn't a solid color. Could I be able to select only the parts that I want to keep, and do this frame by frame? What I'm doing will only be about 3 seconds long. Is this possible with a program like After Effects, or some kind of Adobe program?

**Tags:** after-effects, chromakey


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## 1 answers

### Answer by username_1 on 2017-04-08. Score: 2

This isn't chroma keying. If your subject isn't in front of a green screen (or blue) then you're only other alternative is to mask it, rotoscope to be precise. After Effects does have a tool called a rotobrush that let's you brush around the edges of your subject but it's not the most precise or clean mask.It will however make for a very quick rotoscope. If you go frame by frame, you can make a mask with the pen tool and key the shape each frame as you adjust it. 72 frames at 24 frames per second would give you three seconds like you're estimating. That's about 2 days of work for someone with a decent amount of experience with the pen tool. Hope this helps.

> **Comments:**
> **username_2**: How long it takes also depends on what the footage is. Static shots of a bald guy meditating or handheld footage of a hair metal band crowd surfing at a concert?  

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