Software for automatic masking

#1

hi everyone!

I’m creating a video clip where I’ve insered a 3d model.

The video was taken with a Video Camera upon a tripod, so the camera is always fix for all the video duration.

What I’ve shoot is just a country field, so there is nothing move into the clip (no autos, no people, etc.)

The only figure that moves is just me :slight_smile:

At my shoulder I’ve insered a 3d model and during the video clip I walk in front of it, so what I need is to create a mask silouette of my body when I’m in front of the 3d model.

It could be a bit tedious and long for me to do it precise for all the clip length,
so… what I’d like to know is if is available a plugin for AE or a tool or another software able to recognize into the clip which pixels are fixed (the background) and which are changing so it can automatically build a mask all around my figure.

I thank you very much for your advices.
I hope I was clear enough.

Bye!

#2

After Effects has a built in difference key. Try that. Or roto.

#3

It largely depends on the shot how you handle it. The difference keyer scrimski mentioned sounds perfect for what you are trying to achieve, but make sure you layer your keying effects combined with roto to get the best results. More often than not a single key pull is not going to suffice.

If you are fairly dark/light compared to the background try a luma key as well, but since the shot is stable as long as there isn’t too much grain/noise in the plate you should be fine with difference.

#4

thank you very much for have answered to me!

The effect you refer to I think is “Effect–>Keying–>Color Difference Key”

It seems that I can set in input just a single color even if with some variation, while the figure is composed by a t-shirt, shorts, skin, hair… different colors…

how can this effect help to me?

thank you again.

#5

how can this effect help to me?
It won’t, because I was not refering to this one.
I was talking about the Difference key, which requires a background layer and has inputs for pre blur and tolerance(not sure about the exact names, german version here).

#6

It’s called Difference Matte in English.

Mylenium

#7

Good, thank you, found and tested the “Difference Matte” effect.

But the result isn’t so good, probably for the camera resolution (a standard digital camera 720x576 PAL), or maybe I’ve to wear some gaudy cloths.

Anyway I thank you very much for your help!

#8

Difference Matte takes some fiddling to get a good result, and DV footage isn’t likely to make it easy, especially if there’s much noise in the footage. Here is the process that worked for me:

I saved a frame of my clean background plate (without the actor in it) as a still and reimported it to use as the Difference Layer.

I duplicated the footage and applied the Difference Matte effect to the top copy (the matte layer).

I applied a mask to the matte layer as a garbage matte, set the View to Matte Only, then adjusted the settings until I had an acceptable matte.

I placed the footage beneath the matte layer and set the Track Matte to Luma Matte.

This separated the moving object from the background, allowing me to apply effects only to the actor. The result was not superb, and had I to do it again, I would have shot it in greenscreen instead.

#9

mmm… you’re right Midgardsormr, thank you for your infos,

What about this plugin suit instead?

http://www.thefoundry.co.uk/pkg_plugins.aspx?ui=E86B0EA8-748A-4D53-9FE6-323E0C482E30

“The foundry” company has released a series of plugins called “Fornace” for different compositing softwares (nuke, shake, fusion…)

There’s one called “F_MotionMatte” for auto rotoscoping…
have you ever tried it?

#10

Again let us never forget that there is hardly any perfect one time matte pulling magic. It’s always a combination of techniques, one on top of another

#11

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