Anyone ever hear of this?

[Dr Mordrid]

It sounds like what Mokey does, but with the complexity of extra hardware.

Mokey is software that can remove persons/objects/backgrounds etc. from video streams as if they were keyed, but without the need for a special background. Check it out (1 meg QT file);

http://digitalvideo.8m.net/mokeydog2.mov

Dr. Mordrid

[Brian Ellis]

It has been stated that this is impossible, as I implied with my first lead to gold alchemy. Let me explain why in as simple terms as possible.

Firstly, a blue screen or any other matte should be as accurate as possible, that is to say within a tolerance of 1 or 2 pixels, at the most. This would imply that such a system would need to know, in real time , the exact distance of the object of each pixel. If a given pixel were under a given threshold distance, it would pass the signal; if not, it would substitute the matte colour. It would be useless to have a range-finder system for each pixel which did not go through the lens, as parallax errors would make it useless. On the other hand, it is possible to range-find through the lens onto a CCD by slowly adjusting the focus until one gets maximum differences of signal level on numbers of adjacent pixels (this is how auto-focus works on many camcorders and digital cameras). If this technique were used to determine the focal distance for every one of the PAL 414,720 DV luminance pixels, it would mean that the lens would have to make as many focussing movements for every 1/25th of a second (frame) before focussing on the subject, record the distance in a matrix and calculate what to do with the pixel. Well, you know how fast it takes for a camcorder to auto-focus, don't you? Say, the best part of a second at the best. To do what you are asking, it would have to do it in less than 1/10,000,000th of a second and more than 10,000,000 times per second. No matter how light the focussing components of the lens were, the accelerations involved would be horrendous and you would probably have to have something like a 10 HP motor to achieve these accelerations. This implies a ~10 kW continuous consumption which would drain your 2 Ah battery to 0 volts in roughly no time at all, not to mention that it would need quite a computer with a memory of 512 kbytes to manage the system in real time.

That having been said, simplifications to this basic system could be made. For example, if a pixel, during the scanning process, is the same colour and brilliance as the previous one in the line or in the same position as the line above, then it would be safe to assume that it was at the same distance. This could easily be achieved by ensuring that a blue background sheet was suspended behind the subject, in which case...

Seriously though, how would you determine the distance of a uniform blue sky to decide whether it was in front of or behind the threshold? Have you ever tried filming a flying bird which occupies a small part of the scene, with sky (whether blue or leaden) as the background? If you have, you know the auto-focus will thrash in and out like gangbusters. This kind of shot can be done only with manual focus.

I am not suggesting that there may not be other methods to achieve the same end; I can think of three possibilities, offhand, but they are all impractical. So. I'm sorry, bang it goes into the warehouse, along with the 200 mpg car with a performance like a Ferrari, the gold made from lead, the $750 12 Mpixel SLR adapter and perpetual motion.

Good try, though!

[landrover]

Brian,

this gadget is not intended for filming remote objects. It´s intended for filming your average TV presenter in a medium shot without the need to put him or her in front of a blue screen, with all the accompanying hassles of needed space and lighting. Tomorrow I hope to find out what it´s called and what it does.

landrover

edit: I suddenly remember. It´s a ring with LED´s that´s placed just before the camera lens, tricking the CCD to a certain extend that it registers everything behind the focus-point as equal blue.

[funky-d-munky]

The system wasn't designed (whatever it is called) for the complexities you are stating Brian. It was intended as a studio type device. A way of avoiding lighting and colour keying specialized backgrounds. It doesn't have to do a million calculations. Only one. Anything past x-distance is not captured. That is a constant variable. This distance is hard locked and filming begins.
The debate isn't wether it exists or not( I saw their ads, went to their web page, and read a preview of it in "hot new products" section of a major magazine, I think was DVmagazine))
I just want to know where it is now? What ever happened to this tech and what EXACTLY the tech was.
I am not interested Brian in your interpretation of how you think it defies the laws of pysics and can never exist based only off the info I gave you. Which again based on a magazine I read over 2 years ago!
Brian why do I always find myself arguing with you in so many threads?
funky

[funky-d-munky]

Hey Doc thanks for the link. Cool program. I had never heard of it befor.
Checked out a review and it got high praises. Its main strength seems to be taking objects out of backgrounds, but it's not as good at taking backgrounds out and leaving objects. So far anyway.
As it evolves though I think Mokey will probably be how things will be done in the future. To bad super cool things come with super-uncool price tags ;>)
funky

[miya]

Landrover,

What you are describing is the HoloSet by Play, or a derivative thereof (as DJ stated.) It requires a backdrop, just like traditional chromakey.


Funky,

You don't know how it works. You've never seen it work. You can't even remember what it was called.

Is it possible that you misunderstood what you were seeing, or that the advertisement was misleading? A misleading ad would certainly not be an aberration in this market segment.

[Greebe]

Bingo! No I haven't seen this critter but have a very good idea how it works.

The "ring with LED's" paints an infrared dithered light on the subject (as Landrover mentioned) Now seeing that this light is invisible to the naked eye, but is readily seen with the camera's they tested (based on their IR sensitivity). The camera see's all, but it's decoder (for a lack of a better term) only allows the primary object painted in this dithered IR to be passed through. Anything without it is filled in (Green, blue whatever)

It does not range find, limit or the like.

Drawback, this does not work all that well, requires calibration has an extremely limited range and the available color range in what can be easily captured is quite limited for some materials will absorb the IR and thus will not be passed through. ... Imagine a meteorologist wearing black tie and the maps showing through their chest.

Neat concept, but buggy w/ limited application.

BTW Funky, it's very easy to see how anyone with even the most substantial amount of knowledge in this field would be confused by the extremely lacking info provided. It was only until Landrover mentioned this "ring with LED's" that clued me in on what really was going on.

[funky-d-munky]

Well I seem to recall adjustable depth.
The magazine issue with the ad also featured the product in the "hot new tech products" section that you usually find at the front of a magazine. Both kept talking of the virtues of blue-screenless-blue screening, and as I recall, adjustable depth sensitivity to allow only what you want into the shot. I remember at the time thinking that this was the coolest thing ever and definately the wave of the future. The only thing holding me back was a lack of $2500.
I don't think I missunderstood the ad or their web page. I imagine the tech never panned out and I had forgotten all about it untill the other day as I had not seen anything more on it since.

I was hoping that someone would remember or better yet tell me what that tech had evolved into given the 2 odd year gap.
I did learn of Mokey and I am sure the evolution of blue screen will not end here.
funky

[Brian Ellis]

Funky

"I am not interested Brian in your interpretation of how you think it defies the laws of pysics and can never exist based only off the info I gave you. Which again based on a magazine I read over 2 years ago!
Brian why do I always find myself arguing with you in so many threads?"

a) Because I don't believe everything I read, especially ads
b) Because I try to keep my feet on the ground
c) Because you are "not interested Brian in your interpretation"
d) Because I'm both engineer and scientist
e) Because I'm a Doubting Thomas, dealing in facts and substantial hypotheses, rather than pies in the sky
f) Because I'm an ornery old geezer with well over twice as much experience of our tenancy on this planet as you have.
g) Because, in forty year's time from now, you will be just the same as I am now; you'll think back and say "that incredulous old bastard may have been right", while I'm lying peacefully in my grave, chuckling away

[Greebe]

Well I seem to recall adjustable depth.

Oh boy, here we go again...

Man it ruffles my feathers when anyone who is asking for additional information (and hasn't a clue as to the technology behind it), bashes others in the process and doesn't comprehend the subleties of what was stated when a feasible answer is given.

[gt40]

Here's an idea:
what if you have an image entering a lens, and being split in two directions to two seperate ccd's, one being stopped down to produce a different depth of field and compensated for the resulting light difference. couldn't you then use software to eliminate the non-identical (read - out of focus) bits? The background would have to be a reasonable distance away, but his might work if everything is adjusted properly.

or am I missing something?

[Dr Mordrid]

Holoset uses a special background that, combined with the ring of lights, produces a luminous background that keys almost perfectly with little, if any, spillover. Holoset was developed by Play, Inc.

When Play went belly up in 2000 many of their technologies, including Holoset, were bought by Globalstreams.

http://www.globalstream.com/products/chromakey/

Dr. Mordrid

[landrover]

The Doc´s got it right, again. It is called Holo-ring and it needs a certain glass-fiber cloth as backdrop. This cloth reflects light in every direction, eliminating the need for a straight backdrop. Just pin it to a wall, and off you go. 2 Cameramen at our broadcast company tested it, but the benefit wasn´t spectacular enough for us to buy it.
By the way, the cloth was developed by 3M and this application of the cloth was the result of the co-incidental discovery that it reflects light smoothly in every direction.

landrover

[funky-d-munky]

I am fimiliar with Holoset Play and as the Doc points out it needs a background.

I didn't invent this thing!
I've never seen it!
All I read was a magazine ad, a web page, and a seperate magazine preview over 2 years(maybe 3) ago.

So I am so sorry if people get thier feathers ruffled, or cranky gradpas fall off their rockers. I just asked a simple question."Has anyone ever heard of this?"
Greebe, who am I bashing? Should I cave into you because you insist it is the holoset? No I'm not a technical genius. Never claimed to be. All I've stated is the basics of the ad. Screenless blue-screening. And user adjustable depth. If you don't recall the product, fine. The odds are small. But don't bash me for asking and defending my small brains recollection of what the ad stated.

I mean there are a lot more serious things going on in the world right now. Yet people have to get their backs up over this. This wasn't a do-or-die querry.
It wasn't a market success and as I stated, I only came accross it the one time, in any publication(although I didn't buy every magazine so I don't know.) My intrests lie in what ever became of that tech(good bad or otherwise) any other tech come along after, that also allows screenless keying, or any general discussion of where bluescreening will go in the future.
funky