alternatives to green screen

[Cory Mitchell]

Hey All,

In my never ending pursuit to replace the need of green/blue screen (including looking up those real-time depth cameras) I had an idea that would use a focus assist type system, the kind where if something in focus is highlighted or something like that. Does anyone know if it would be possible to output a focus matte? (like metadata)

Does anyone else have any other ideas that could pull a key without a colored screen? Could a seperate camera be used?

thanks

visionmind

[Chris Kenny]

Some films are using roto extensively instead of chromakeying. This isn't very practical for indies, though, as it's extremely labor-intensive.

There's already software which can do optical tracking and take a fair bit of the work out of roto. Machine vision technology is advancing pretty fast, and in five years there might be software which does pretty good roto without much human help, but we're just not there yet.

[Mark L. Pederson]

Some films are using roto extensively instead of chromakeying. This isn't very practical for indies, though, as it's extremely labor-intensive.

There's already software which can do optical tracking and take a fair bit of the work out of roto. Machine vision technology is advancing pretty fast, and in five years there might be software which does pretty good roto without much human help, but we're just not there yet.

We use MOTOR - VERY powerful tools for roto -

http://www.imagineersystems.com/products/motor/

you can download a free trial version -

[Cory Mitchell]

I've checked out motor (and every other program I could find) and it seems that software could prove very helpful in the automation of the matting process.

What about any hardware solutions? (using two cameras somehow?) or other new ideas to create mattes without a greenscreen?

visionmind

[Jim Arthurs]

What about any hardware solutions? (using two cameras somehow?) or other new ideas to create mattes without a greenscreen?
visionmind

You could use a blue screen instead of a green screen. :)

Just joking, I know what you're asking, and the bottom line is it simply isn't possible to do anything that would be remotely considered "film-quality" in terms of a key. Semi-transparency would completely fail in something that uses depth information even if it was perfect in every other way.

[Bruce Allen]

If you look at the history of film, a lot of things have been tried.

Hitchcock even examined a lot of crazy options (eg shooting simultaneous infrared, etc) back when he was shooting The Birds...

So yes, you could:
1. shoot greenscreen
2. shoot sans greenscreen and use roto, maybe combined with sophisticated guided image analysis / difference matte software
3. get fancy and try and shoot simultaneous infrared or something
4. along those lines, lidar...
5. shoot stereo (or many angles, even) and develop an algorithm to use stereo info to assist your roto
6. use a very high-fps system (with synchronized strobes, etc) combined with high speed cameras and optionally, fluroescent paints ;)
7. Combining #2, #5 and #6, do a multi-cam motion capture system and map out actors in moving 3D space...
8. Combine all of the above!

Personally, I think we should maybe just teach tribes in Africa how to roto, pay them in dollars and everyone wins.

Of course, roto is a skill. Sometimes it requires considerable figure-drawing ability as you are essentially creating a human-shaped outline from a dull blur.

Cheers

Bruce Allen
www.boacinema.com

[Jim Arthurs]

Don't forget the Disney dual movement sodium-vapor process used on Mary Poppins. 'Course they could only make the one beam splitter that actually worked for passing the narrow yellow band of light...

[damonbots]

Dammit, Jim!

You've got me wondering...
What is the Disney dual movement sodium-vapor process?

[Chris Kenny]

Personally, I think we should maybe just teach tribes in Africa how to roto, pay them in dollars and everyone wins.

Maybe you're making a reference to this, but... I listen to This Week in Media (http://www.pixelcorps.tv/this_week_in_media) every now and then, and one of their regulars does work in Zimbabwe. Apparently what you describe is essentially happening.

VFX houses had the idea to farm this sort of thing out to India a few years ago. So much work has gone there now, and it has gotten so good, that it's barely cheaper than the work in the US.

[Bruce Allen]

Maybe you're making a reference to this, but... I listen to This Week in Media (http://www.pixelcorps.tv/this_week_in_media) every now and then, and one of their regulars does work in Zimbabwe. Apparently what you describe is essentially happening.

VFX houses had the idea to farm this sort of thing out to India a few years ago. So much work has gone there now, and it has gotten so good, that it's barely cheaper than the work in the US.

I am from South Africa. When the government telecommunications monopoly that is screwing everyone over and keeping us on dial-up finally dies, our VFX industry will really have a chance at taking off.

However, being in LA now, I understand that there is a good reason that many, many things will always stay local.

Bruce

[Bruce Allen]

Don't forget the Disney dual movement sodium-vapor process used on Mary Poppins. 'Course they could only make the one beam splitter that actually worked for passing the narrow yellow band of light...

Jim, tell us more! I watched Mary Poppins at the El Capitan the other day. I was actually quite impressed by some (not all, though ;) of the SFX....

Also, do you know what was up with the recent print? It looked like they did a DI and tried to simulate Technicolor by pushing the saturation in weird directions... interesting but looked a little fake and plastic to me. Anyone else see this?

Bruce
www.boacinema.com

[Jim Arthurs]

You can call this process "yellow screen".

Okay, you take a Technicolor camera, and a beamsplitter prism designed to pass only yellow light at 589 nanometers and a bright yellow screen (lit with sodium-vapor lights) behind the talent.

The foreground is lit as normal, and recorded onto early Eastman negative that was rather insensitive to saturated yellow of narrow range. Since the Technicolor camera has multiple gates and mags, one head records the color image, while the special beamsplitter shaves off the yellow and passes it to the monochrome yellow sensitive b&w stock, producing the matte on the other head. Of course, lots of spill issues, and nothing resembling what we'd call "spill control" either... but it worked to good effect (the merry-go-round sequence, for instance). The rumor is they could never make another beamsplitter as good as the first so the technique fell to the wayside when bluescreen processes (requiring a single negative) came on the scene.

I would really like to catch Mary Poppins in the theatre, maybe it will hit town, but haven't heard anything about the restoration process...

[Chris Kenny]

I am from South Africa. When the government telecommunications monopoly that is screwing everyone over and keeping us on dial-up finally dies, our VFX industry will really have a chance at taking off.


Some less developed countries are leapfrogging even Europe and the US. Rwanda is doing a major fiber rollout, for instance (of course, it is a pretty small country, which makes this easier). If you don't have much infrastructure to begin with, you're much better off these days installing fiber (and wireless) than installing copper and upgrading later.



However, being in LA now, I understand that there is a good reason that many, many things will always stay local.


A pattern that has emerged with Indian VFX is that American companies just open branches there. You might be handing shots over to an LA company, and some of the work might be getting done in India. You'd never know. And as one of their clients, you wouldn't have much reason to care. There's still an American staff the director or whoever can work with on the days when that's necessary.

[Thomas Mathai]

Seems you're looking for a short cut. There are really no easy short cuts.

It makes sense to plan out shots and use the right technique for the job.

There is university research on various auto compositing techniques, but there hasn't been any product I have seen yet. It's all interetsing and we'll see what the future holds

[Jim Arthurs]

And overall, what's really wrong with blue screen or green screen, unless you're doing a super hero movie where the costume is half saturated blue and half saturated green?

Color Difference Matting is a very mature art/science and can be almost perfect with today's tools. Folks, we've got it EASY compared to just a decade and a half ago. I was cleaning out some boxes of old elements today to put in (better) storage and came across some of my old optical blue screen shots. Photochemical blue screen is HARD under the best conditions when you have your own lab or daily access to their gear. Then imagine putting yourself out in Podunk Ville in Colorado in the 80's where the local lab ain't exactly thrilled to mess with their gamma on your 25' b&w run and they only do b&w twice a week...

The only way I could describe it in modern terms is to compare it to adjusting a slider in your composting app and having a message come up saying "check back in 24 hours to see the results of your incremental tweak". Then, as an added bonus, when it pops up, the matte may have been translated or scaled just a bit without your input at all, randomly.

Enjoy your keylight/Primatte/Ultimatte...

[Michael "Dorkman" Scott]

A pattern that has emerged with Indian VFX is that American companies just open branches there. You might be handing shots over to an LA company, and some of the work might be getting done in India. You'd never know. And as one of their clients, you wouldn't have much reason to care. There's still an American staff the director or whoever can work with on the days when that's necessary.
Even ILM has a branch in Singapore.