help with rotobrush

[stefanocps]

Hello i am trying to use rotobrush to isolate the dancer . Is going to be hard job i think, (it is 5 minutes video) but i need to remove the background.

SO i am trying to learn to use rotobrush and watching tutorial

There is one thing it is stopping me. I can't select the whole body, because if i try to select what it is still missing, a big part of the frame will be selected too

 You can see the rihht hand and the left foot aren t selected because of that.

Also there is a problem with the left arm, as it will select a part of the background

Any help apreciated, thanks a lot

[stefanocps]

i have used the white balance corrector to make the waal better different rom the skin. I could go a little further with roitobrush, but still need to select some parts

[Mike_Abbott]

I don't want to be too discouraging... but have you done the maths? 5x60x25(?) = 7,500 frames.
and the video (subject / background - setup, colours, tonal range...) could hardly be less suited...

I'd you suggest you step back and re-think. Seriously.

[Rick Gerard]

This is going to take a combination of techniques. Rotobrush is going to only work on part of the scene. The motion blur and hair are going to be very difficult to deal with. You are going to end up with a bunch of copies of your footage, a fair amount of manual rotoscoping and mask animations. Here's the basic setup to start:

The exposure and color balance is terrible. Simply matching the output of the Red, Green and Blue channels will get you close enough to use Extract to remove most of the white back wall. That is going to leave holes that you fill by adding animated shape layers that can be used as track mattes or by adding masks that can be used in the compositing options for extract. That will leave you the darker floor. Rotobrush may, and I mean may be able to help separate the dancer's legs from that background or maybe you want to leave the floor. The motion blur is going to be a problem that may require a duplicate copy of the footage with a carefully applied Rotobrush Refine edge applied to an animated mask over just the motion-blurred part of the image. 

I have been doing this kind of work for about 25 years with all kinds of software and before that by hand painting masks on animation cells. If a client brought me your 5-minute clip I would quote them 40 to 50 hours to pull a good matte. If the footage was shot at a higher shutter speed to eliminate most of the motion blur, properly exposed, and a little more care had been taken with costume, lighting and removing things like the box in the background that estimate would drop to about 4 to 6  hours. If it was properly shot against a background that could be keyed we are talking about an hour.

All is not lost, but you'll probably need a couple of weeks to get the technique down and successfully remove the background.

[stefanocps]

ok i can see that nothing is lost but is going to be an hard job

I forgot to mention that the second part of the 5 minutes video is with 2 dancer. Don't know if this get th ethings more complicated. Also i have another footage where to get close up from, that means that it will require to be treated not all

What scares me more is that i have amost zero knoledge of after effcts nad looks like need to combinate more tecniques for the job to be done, as Geard said..and it takes a while to understand even what you write, before all

ANyway, the idea of reshot is the latest possibility as i don t know if i can do that

I also will be satisfied with other method that let me use the footage even if the dance will be somehow transformed. I was trying to do that with ultrakey, and i am almost there, but still something not good. It would me fine for me to transform it in a kind of videoart style footage

this is how.To tell the truth i would rather doing somehting similar..somehting "oniric". This frame is good but not all of theme are like that

ANy help toward this direction is also really appreciated

thanks

[stefanocps]

Also @Rick_Gerard can you explain me more about "matching the output of the Red, Green and Blue channels(simple level clor correction) and the use of EXCTRACT to remove white background

Thanks