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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.
Here's a Press Release...
+5, Female
Here is another atricle about it that includes a picture of the display. This one isn't Slashdotted.
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.
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.
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.
FunOne
And the mostly content free first page.
This will be a good test of my provider :)
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.
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.
"We don't know what we are doing, but we are doing it very carefully,..." Wherry, R.J. Personnel Psychology (1995)