Extracting the matte of a moving object?

#1

Hi,

I am quite new to combustion and am trying to extract the matte of a person who is moving accross the screen from some video footage.

Could anyone suggest a solid workflow to deal with this?

Thanks very much for any suggestions

Spence

#2

Welcome to the world of rotoscoping. Basically you are going to have to create an animated matte that changes each frame. To speed the workflow I do the main keyframes every 10 or so frames, this can be any nth frame as it is just a starting point for the rough matte, and then clean up as needed.

-Eric

#3

Oh I see. Are you suggesting to paint a vector silhouette every ten frames or so then animate the shape basically morphing between the changing silhouette outline?

I was wondering if you may be able to track the outline and then clean up…?

#4

Actually you create one shape and animate the points every 10 frames or so. This way you are dealing with one mask. You can track the mask points but that can be difficult depending on the footage and the motion of the subject you are wanting to track.

-Eric

#5

In a program like combustion* you could, but wheter that’s more effective (which is less time consuming) than rotoscoping by hand I’m not sure, because when you rotoscope by hand you have more control.

#6

The only thing that worries me about animating one shape to rotoscope the movement of a person is that as the person walks or swings the arms the shape will drastically change.

Wouldn’t it be easier to animate several shapes one for each part of the body ie. the head, both arms, both legs and the abdomen as these shapes should not change significantly?

#7

Actually its not that difficult as combustion has the ability to animate mask/paint points on and off. However, you could do it with multiple mattes if you choose. Everyone has their own workflow, you should use the one that is most comfortable to you.

-Eric

#8

Ok well thanks very much for your help on this Eric and Marco. Im gonna start and see how it goes.

Spence

#9

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.