Seamless Video Walls

ahfoo writes "A company called Seamless Display is shopping around a new way of hiding the seams in video walls that mostly relies on modifiying video drivers to achieve its effects. According to their press release they hide the edges between monitors with a bit of plastic film and compress the video at the edges to produce a more or less seamless image. " Really bizarre, but it looks interesting.

Comments

Hope it's better than the last one...

[Dr. Manhattan]

...that was mentioned on Slashdot.

Re:Hope it's better than the last one...

[Anonymous Coward]

Doesn't sound like the same thing. The company in this article makes a video wall. VisualLabs tried to make large LCD display using smaller LCD panels. BTW, this company developed tiling LCD technology. They currently have a 37.5" display (due to technical and financial issues, the large monolithics have caught up) that is made from three 21.4" LCD tiles (two seems). The seems are not completly invisible. In all but low contrast (mainly black) images are the seems completly invisible.

The way they do tiling is to cut as close to a column of LCD cells as possible. Laminate the LCD tile between two pieces of glass. Then vary the gamme curve per pixel around the seem to blend the image between tiles. Also, the tiles are custom made, and driven from one edge.

BTW, I work for RDI. They are just now starting to sell the 37.5" model.

Folding LCD screens

[Brahmastra]

The best application for consumers looks like the folding LCD displays. It would be great to have handhelds with a folding screen without a perceptible seam. Finally it won't suck to play games on handhelds.

Re:Folding LCD screens

[Oculus Habent]

There's still a perceptible seam, and the span is somewhat distorted. Not the greatest for details.

Rear Projection

[jhines0042]

Wouldn't a video wall be better served by having several rear projectors that line up perfectly rather than trying to eliminate the frame of a CRT?

It seems to me that with a good jig and a consistent set of projectors, and some good use of mirrors if depth is a problem, that you should be able to get a seemless image with very little work.

Re:Rear Projection

[Sphere1952]

You've got an extra room to devote to the task?

I think computing paint would better serve the purpose. When will I be able to just paint a monitor onto my wall? (And I bet the fumes will be carinogenic.)

Re:Rear Projection

[CaptBubba]

They wouldn't have to even line them up exactly.

I saw a demonstration using a beowulf cluster (well, part of one) that was rendering a moving 3-d CAD model. They just threw the projectors so they were somewhat aligned, used a webcam and had one of the nodes look at the overlap and correct for the projector's misalignment in real time. ~20 other CPUs were doing the rendering, but it only took one to make the display come out right. I would imagine the same thing could be done for a rear-projection screen. As long as the projectors didn't get jostled after being observed by the computer it should work fine.

Re:Rear Projection

[Aidtopia]

This is a standard multi-image trick. It works with front or rear projection. To get the images truly seamless, you overlap the projection areas (anywhere from 10 to 50%) and use a grayscale gradient mask to blend the overlapping areas. This technique was perfected with those zillion-projector slide shows from the '80s.

The trick lives on today with video projections. Dataton has a product (Watchout) which does it in real time with a network of computers. And, as another poster pointed out, aligning the projectors is less of an issue, since you can now use a cam and some extra cycles to warp the projected images rather than adjusting the projectors.

Re:Rear Projection

[Dirk.Reiners]

There are a bunch of these around, the keyword to look for is tiled display. It's been an active topic in the computer graphics and virtual reality community for the last couple years, and people have been building different sizes and using different alignment methods. The biggest ones I know are the NCSA 40 node and our 48 node system. Most of them are mono, there are two stereo-capable systems, one in Boston, the other one is ours.

The problem with the "rough alignment, use computer vision to sort it out" approach is the overlap area. Current projectors have a pretty sucky contrast (black to white) ratio. In the overlap areas all the blacks are added together, so the actual black you get is already pretty bright and there's nothing you can do about it. That's why we decided to go the hard route and do exact alignment. It's hard, but it's doable, and the results are pretty cool.

The presented method avoids that problem by design, so that's what makes it interesting, IMHO. Beside the fact that it doesn't need a separate air condition and 3 m back-projection space...

Interesting, but

[Oculus Habent]

Having to change the video drivers to "compress the edges" seems like a messy task. I don't see any information about control software that lets you choose which edges are compressed, either.

A little sparse on technical detail, though that is somewhat expected... I want to know where the "compressed image" it talks about comes from. Does it create additional "virtual pixels" that cover the gap, and then mash them into the few on the edges?

Re:Interesting, but

[CausticWindow]

I read about this in another article (can't remember where though) that it compresses the edges (10-20 pixels) with a discrete cosine transformation (as in jpeg). They could use huffmann, but that would make the edges jagged, and the screen wouldn't be seamless anymore.

The reason that they have to do this in the driver is that they have to hit low level to get decent speeds (windows display drivers can hit the hardware directly, contrary to most other windows drivers).

Psssh....

[JoeLinux]

Big deal. I'm wating for the DirectBrainX from Microsoft. Just plug directly into the base of your skull and watch your will to live drain away.

Blue screens now resulting in total loss of bowel functions!

*sniff* I'm getting misty just thinking about it.

Possibly already an irrelevant technology

[heironymouscoward]

OLEDs are almost there, they are already being used in small portable devices (cameras and phones). They can be scaled without the fabrication issues that hit CRTs and LCDs. There is a good chance that OLED screens will be the first consumer-ready wall screen system (the current best of breed being the projector).

But this looks fun, and it may be a good stopgap. I'm wondering whether it can be used to build (for instance) large LCD monitors for PCs...? I once had a portable that used two B&W LCDs to achieve a larger display area, but I've never seen this done with color LCDs.

What I really wonder is..

[blankinthefill]

What does this mean for the MS Flight Simulator Groupie?!? Are we going to be getting entire "flight rooms" now? AHHHHH!!!!

Right on!

[Talia Starhawke]

One word:

PORN!

Re:Right on!

[mopslik]

One word: PORN!

I don't know about you, but I believe that some things are better not seen blown up 20X.

Hidden page

[jarda]

Obviously, now they have compressed and hidden their whole page before slashdot crowd. So, it seems to be working.

Try draper as well

[Stonent1]

www.draper.com Back when I installed Air Traffic Control simulators we used Draper screens. I was looking at the Draper site and they said they had seemless displays and this was about a year ago. We could get pretty seemless with the large screens that we had.

Oled's are they the saviour of lcd tech?

[way2trivial]

after reading the pieces on CDR's which use organic dyes, and the organic dyes don't last beacuse they break down, I wonder about the long term viability of Oled's. Aren't those organic components subject to the same rules of degradation as the organic dyes?

Re:Oled's are they the saviour of lcd tech?

[stratjakt]

The fantasy is that OLED will be so cheap to produce, it wont matter to you. Your roll-up wall-sized screen will be priced like drapery fabric at the local craft store.

So when it fades, you'll be able to replace it cheaply, just like replacing the faded Pink Floyd poster from your college days.

This, of course, has been the promise of most new tech. Super-cheap and disposable. We'll see.

Mirror

[Talia Starhawke]

Here's a Press Release...

Technology....

[$exyNerdie]

Well, it seems that they use a lens coating to correct image corners (could be affected by wear and tear). I thought it was ONLY a software based change in display drivers.

Reasonable, but not great, idea.

[Animats]

This is a plausible, although not great, idea. Optically expanding a display screen a bit to merge the edges have been tried before. It's possible to expand the whole image without parallax using a big fibre optic plate, but that approach is heavy and expensive. This approach apparently only messes with the edges, squeezing them digitally to compensate for an optical device (probably a plastic Fresnel lens) that expands them to cover the gap. The compressed region also needs an intensity boost, since fewer pixels are filling more area. From the pictures, they didn't do that, so there's a dim line at the joint.

We'll have to see how good it is, and whether it looks any good from an off-axis viewpoint.

"Doctor, I want a system where everything comes out of one hole." Mike Todd, producer, to the head of American Optical, discussing wide-screen projection.

Here's another article on it w/picture

[FreeLinux]

Here is another atricle about it that includes a picture of the display. This one isn't Slashdotted.

Re:Down?

[bighoov]

Could it be that people are actually (shudder) RTFA before posting?

It's the end of /. as we know it!

LCDs are already organic :P

[purduephotog]

They use organic polymers - dyes are organic. Everything fades. Your laptop will fade. OLEDs sometime do this faster, sometimes slower.

Now if only...

[johnthorensen]

Now if only they could apply this technology to the scars from my woman's boob job :)

-JT

Now only if

[Bruha]

They put in a few more dollars on that webserver and their slashdotting would of been seamless.

Re:Rear Projection - Clemson University

[FunOne]

Clemson's Beowulf group is currently working on this exact topic, except you have ~7:1 fan out on the graphics nodes for rendering, IE, you have 7 computers rendering, sending the frame over 10/100 to the switch which has 1gig to the display node that outputs it.

It looks pretty sweet and they're getting there on real time graphics. All the projectors were just put back behind there on a rack (24 I think) and software + webcam is used to align and create a striaght and hopefully soon, color accurate picture.

A leetle Mirror

[teamhasnoi]

Here's one page with some pics.

And the mostly content free first page.

This will be a good test of my provider :)

It's called Edge Blending

[green pizza]

I've seen SGI and Barco (the projector company) do this for over a decade on their massive multi-projector screens. (As have Panoram and others...) It's a combination of software (generally image overlap) and hardware (soft edges) that produces an invisible seam. With modern high-dollar projectors there isn't even a noticable difference in brightness anywhere on the screen.

Keep in mind that these sort of professional "reality centers" generally have very precise and predictable optics, these aren't the sort of projects you can buy at Staples or Frys. Cheaply made LCD projectors had a nasty habit of discoloring and changing their output look over time, especially when run for several hours every day. DLP has made a life a lot easier, but the cheap projectors still can't handle continuous use. Shop around and talk to the experts before you plunk a bunch of money down on an array of projectors.

Re:Rear Projection - Clemson University

[DarkSarin]

Interesting that you should mention Clemson, since I also know that they use a similar (though not exactly the same) setup for the driving lab in the Psych Department. They don't have them clustered quite the same, but essentially you have a control box (for the steering and pedals) connected to a relay, which converts the signal to 10/100, which then runs the signal out to 4 different computers that each run one screen for the "car". These are all linux boxes, and there is a final box running windows that is used for setting up scenarios and monitoring subjects' responses.
It's really a sweet system.