Removing backgrounds

I have a shot of a kid stood in front of some set elements, and i also have the same shot without the kid.

Is there any clever way to extract the background from behind the kid without resorting to gmasks?
I can’t key - the way its been lit means the kid is lit with many of the colours in the background.
I can’t be arsed to roto it either.

Neat both clips, then take the locked off BG sans talent, and average the clip over like a second to further remove little temporal stuff. Try difference matte between the two. Doubtful it will get you all the way there, but could at least help in some areas.


Thanks GP…trying it now!

Let us know when you give up and start rotoing. :slight_smile:


Also, what Randy said.

probably not long now!

The other way to avoid having to do roto on this, is to send it to a cheap roto farm. :slight_smile:

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was also trying the machine learning stuff but thats too random and rough in its results

Is it just one shot? How long? If it’s not much, I really would just send it to a cheap roto source, if you don’t want to experience the pain yourself.


that involves paying others…which is why i am employed in the first place!

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Well then, welcome to the suck…

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I once made progress on something like this using subtract or something with the two clips. Didn’t give me a full perfect matte of course, but got me further.


it was a long shot, but i hoped you could do some maths that tells an image to remove all pixels that are identical between two shots. Then whatever is left forms the basis for a matte that would need other work but get you a long way there.

ok…roto it is

That’s essentially difference matte.

Have you ever used outsource roto? It might only be $100.

thanks Peter - was hoping for something inside Flame (hate AE and have managed to avoid using it for nearly a decade!)


runway ML has a free trial.


This is a non-Flame solve, though there may be enough in the paint tool to do the same: I just did this on a shot where a prop rope was visible in an action shot with lots of motion blur, and it overlapping background differently in each frame:

In SilhouetteFX use the paint tool and paint from other input (alt clip)/with frame offset (same shot). You can combine that with a tracker.

In my case often the offending section was clear a few frames to the right/left in the sequence. Do a quick track of the area, set the brush to frame offset and source match move and simply paint the background back in. Big & fast strokes, no need to be pixel accurate in stroke. Tracker takes care of that. Works really well.

In Silhouette you can also adjust exposure, color, scale, rotation and a few other things on the brush stroke, so if exposure shifts between source/dest you can compensate for this easily.

I think SilhouetteFX works as an OFX plugin in Flame as well if need be.

SilhouetteFX still sets the standard with paint functionality. And it’s vector based paint, so editable and automate-able to a degree. Though some edits can be quirky.