Rotoscoping / Keying out twigs (Use a Track Matte?)

Rotoscoping / Keying out twigs (Use a Track Matte?)

by Cesar Vargas

on Jan 9, 2018 at 12:46:17 am

m working on a clip that is about 2minutes long, and has a face behind a bunch of twigs and branches, and I need to blur the face out.
I was wondering what techniques you guys would do in order to keep the sharpness of the twigs and branches.

I've done this clip by rotoscoping, but it does take a really, really, long time, and I wanted to see if there was a smarter way I could go about it.
I've heard that maybe a track matte might help, but I can't seem to get all the twigs in one go, since the twigs are different shades of green, grey and brown.
I've tried the color key, keylight, and extract effect, but none really get all the twigs in cleanly with a good sharp edge on them (Some of them are out of focus.)

Also, when using the extract tool, should I be in Lab color mode or RGB? The main delivery system is TV.

Has anyone encountered trying to key out something like this? Any tips would be appreciated!

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Dave LaRonde

on Jan 9, 2018 at 1:42:13 am

You may be better off building a procedural matte. Since we can not see your work, we can not tell you precisely what to do.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Stephen Smith

on Jan 9, 2018 at 3:30:07 pm

Are you blurring the face because that is what you want or because you can't show the face? If you don't want to see the face I would do a 3D track and cover them up.

Stephen Smith

Utah Video Productions

Check out my Vimeo page

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Cesar Vargas

on Jan 9, 2018 at 6:18:11 pm

I apologize for the lack of video, I know it's frustrating to know what I mean without having an example. Maybe these sample links will help:

Woman behind twigs
https://www.videoblocks.com/video/female-checking-vineyard-branches-medium-...

Blurring Man behind twigs and branches
https://www.shutterstock.com/video/clip-16967941-stock-footage-professional...

Another example:
https://www.shutterstock.com/video/clip-32512873-stock-footage-young-grower...

Probably the best example:
https://www.videoblocks.com/video/active-man-gardener-prunes-and-trims-bush...

I need to blur the face for anonymity, but also, I sometimes get shots where I have to blur things underneath (Face, logos, etc). In the first example, I would probably Roto it, but in the 2nd and 3rd examples is what I deal with. I know the first response may be "get a better shot" but I work in the part of the pipeline where they just give me a clip and need to blur out a person's face..Just curious to see if there is another way other than Rotoscoping.

Stephen, sorry, I still don't understand what you mean by doing a 3d track to cover them up..Do you mean 3d track the branches, and create masks for them?
(By the way, great work on your page!)

Thanks for the response guys, I really appreciate you guys taking the time out of your day to help!

-Cesar

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Dave LaRonde

on Jan 9, 2018 at 6:39:52 pm

Any time you blur the video in post you'll get both the subject AND the twigs blurred. So you will see vestiges of the blurred twigs, even if you roto the twigs on another layer. There really isn't any way around that.

It sounds as if you really need a shallower depth of field when you shoot so you simply get it right in the camera.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Cesar Vargas

on Jan 9, 2018 at 8:48:42 pm

Ah, ok..I was wondering if there was a way to separate them out and create some kind of matte...

Thank you for that response!

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Dave LaRonde

on Jan 9, 2018 at 8:57:27 pm

Well, you could do it in two shots. One would be shooting the subject out of focus with NO twigs in the foreground. Then you you could shoot the twigs on a chroma key background. Key the twigs over the subject.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: Rotoscoping / Keying out twigs (Use a Track Matte?)

by Stephen Smith

on Jan 10, 2018 at 2:26:24 am

Cesar,

Thanks for the kind word about my webpage. As for the 3D track. I thought you wanted to just get the person out of the shot. I was going to suggest doing a 3D track and placing additional branches in the shot to cover the person up. But it sounds like you want them in the shot. Unfortanly you will have to rotoscope which will take a long time. Sorry.

Stephen Smith

Utah Video Productions

Check out my Vimeo page