Photo booth like removing background

monsieurmeus

Hi falks!

I'm trying to do a very simple video installation but I need to do just one thing that is removing the background so I just have people visible (or anything that move in front of the camera).

A "flood fill" won't work since my background is not regular or monochrome… any idea ? I'm getting worried…

all the best to you all

Skulpture

This is obviously your problem "background is not regular or monochrome" the easiest way to do it would be to make the background static.

Erm; this is an awkward one. With a couple of possible solutions, but its difficult to know which one might work best for you.

What is the background, is it constantly changing? I'd like to know what the background will be.

Would you be able to take a screen shot of the background using 'freeze' actor and then remove the background using difference via the effects mixer? A bit like what I do for motion tracking? (Tutorial in my sig on my blog)

monsieurmeus

Hi !

oh that's a brilliant idea ! Yes my background is static, I should have think of freeze & difference, I'll try as soon as possible but I think you solved my problem !

thanks for your rapidité, merci beaucoup

eight

Did you consider using kinect? Possibly kinect augmented with a DSLR (if you need high resolution RGB)?

--8

MatthewH

I have done this rather easily with a Kinect. Fred's kinect server will actually do this for you automatically.

monsieurmeus

Thanks eight & Matthew for the Kinect tip. Yes I have Kinects but I never used it within Isadora so that mean that I'm really a very beginner in that. I couldn't find in the forum something like "how to use a kinect…" is there something like that somewhere ? If you say it's rather easy, it sound good to me. I didn't find "Fred's kinect server" you're talking about, am I searching the wrong way ?

eight

@monsieurmeus check old forum, I think all of the kinect patches are there: you would need a mac though, because those patches rely on a QC patch and a plugin.

--8

monsieurmeus

@Skulpture
Hi again, sorry to bother you again for something so simple, but, I still get my background in transparency using the technique like you said… It must be simple but still can't find the way like this, I hope I don't have to use a kinect method for that.
sorry again…

vanakaru

You need to trigger ”grab”(I have generator, but can be anything like keyboard watcher etc) and video you grabbing from goes to first input.

Also I have made it into user actor - it is so basic that you need it almost always for tracking.

2d249f-backgrnd-subtr.izz

Skulpture

Yes. Move out of the way of the camera then somehow (without the camera not seeing you!) press 'grab' on the freeze actor and then move back into the frame.

It's a start.. you then might need to look at making it look much better.

monsieurmeus

thanks a lot for your help and your rapidity! but I still don"t find how to make the image look normal, I mean, not transparent with negative colors…

monsieurmeus

and maybe you can help me also to find the Kinecttoizzy QC plugin, I search and search and can't find it to download… new or old forum… sorry again

DusX

EDIT: don't use this method.. its an unfortunate early attempt ;)

I have added something just like this to my livefeed option in SYST3M, unfortunatly the next version its far from ready to share (not working perfect yet).

I think what you want to do is (at least what i did) is use a buffer actor to stream into your difference actor.
Your buffer needs to be 2 frames and being filled with the freeze frame and your live feed, alternating at the same rate as your FPS (I used the 'Performance Monitor' to set the rate of a Pulse actor->counter->selector. there might be easier ways).
Since the difference actor looks at 2 frames (in sequence) of 1 video stream.
This will give you a black and white video stream of the 'change', which should be you.
You can then use this stream to add an alpha or mask your stream onto another background.

I'm attaching a screen grab of a sample.
You can see that I stopped using the pulse as the trigger, since the live feedfeed seemed not to be the same FPS as my stage.
In anycase this is kind of working.. but I have a fast video flicker.. this might be an issue with my buffer setup.. not sure.
Its a start.

vanakaru

try my sample patch

DusX

Heres one that is working pretty well for me.

6e4c48-removebg1.izz

DusX

note: like Skulpture mentioned before, you need to grab a freeze frame that is of the static background first..
then you may need to play with the threshold and other actor settings to tune it up.

Michel

and it does help to switch the camera from automatic to manual settings.

Skulpture

I like @DusX solution using the AlphaMask!

* I might have to recreate that patch and steal it for my collection ;) *

nick

if lighting changes you will also need to grab a fresh background frame - depending on your situation it may make sense to grab a fresh background frame whenever the total movement in the frame is less than a threshold - this will help protect against slowly changing light levels

DusX

@nick I was thinking of adding a motion detection based reset as well, good call, since half the work is already done.
@Skulpture go to it.. would love to see what you are able to add to it.
@Michel you are so right I was just playing with this with a cheap webcam that is all auto focus, auto white balance etc.. and it simply didn't work at all anymore.