Easy multi-projector desktop using Lighttwist compiz plugin

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Video in TIB AV-Portal: Easy multi-projector desktop using Lighttwist compiz plugin

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Easy multi-projector desktop using Lighttwist compiz plugin
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We present a new compiz plugin to use multiple projectors, in order to obtain a very high resolution desktop (with two HD projectors, the desktop is typically 3800×1000). The most important feature is that projectors alignment is done manually (very quickly) and the edge blending is computed automatically. The result is a perfectly aligned, anti-aliased and edge-blended desktop.
Keywords Libre Graphics Meeting (LGM) Libre and Open Source graphics software
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Server (computing) Arithmetic mean Touchscreen Computer animation Real number Multiplication sign Flag Game theory Game theory Computer programming
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the assignments of a satellite and there is also a weak shot you with me in the front has some really happy here we really happy to be here to represent something that is that might have unfamiliar to some of you because we presented light with a lower um multi-projector project 2 years ago it L G M here anyway so the project today is easy multi-projector that stuff using like twist on the company's plugin Seoul companies going to actually so well a quick
overview so I'm not going to stop about it you know the I'm I'm just going to remind you of what we like this project is and then the Commission company is how to align projector and there actually were the of a quick thanks in our lab at the University of Montreal the uh in the computer science department there are many students working in computer vision and so what you see here is a branch or a sidetracked of many of the work we do in the students working on this slide what is so what is
like well it's a multi-projector immersion software that tries to allow you to project with many projectors on any surface you want in the key of this system was that the don't aligned by hand use a camera In the camera is going to take pictures of the screen and align everything automatically very soul if you were there 2 years ago you saw a demo of a cylindrical screen so that the with like now the key in a system like this is that you you have up to if they 12 projectors and you need lots of machine in the synchronized by network it's a it's a pretty complicated set and it's very it's very nice but it's complicated so I would say the problem with that is that no 1 can actually use that very simply when they have few projectors so the goal of the to actually propose something a little bit better so this is a
reminder of the screen that we brought here 2 years ago and it was pretty big 5 . 8 . 5 well almost 5 meters 7 projectors it's a quite a few people in a few hours to set up so this is not the typical tree set up in your living room to watch a movie and by the way that we are working we have version of this in our land which does also stereo projection so that stereo cylindrical versus stereo projection very nice and there also double the part the troubles you 1 and so some people here might
recognize them so that can last year by year you value that she that it's odd to recognize people with the little square in the face but anyway that was inside the screen that you now the so our goal is to
make multiple ejection very very simple and we figured the only way to make this simple is to forget the requirement of having a player software that will play a video and images and things and that so the only way to do that is to actually distort this stuff that the best itself and the way to do this is to use companies on it works really well so the company is if you don't know what it is is what makes all the window jiggle all the fancy open effects on the best of 1 thing that it does that you can do very well is to this story images so we figured actually why not create a standard plug-in that people can just put on the desktop that will help them aligned projectors so that's the idea and actually this question at the plug-in becomes extremely simple to use OK so how does it work exactly
well you use this distortion plug that you just enable and then you need to create what is called a lookup table that will just take pixels from the screen in Figure where they should come from from the desktop and it would be the the the the the selection of the text and it comes in the form of the RGB image so that it's easier to look at I look at it's a 16 the MIT PNG delight away at a word about it in the the the front to edit the image then you use the creator which which may well but I might add a feature requests for that I regardless not preserved text back into PNG files then we do find a lot of information in there that text that tags of PNG files that it would be nice to read the book save them or maybe maybe I'm wrong really are a very good because that was the best of the new formation of the
only stored the brush presence in PNG files we just rename it to keep the then reused as part of the file just stored that the so we have the book so we
thesis that very good so actually this is a very nice addition because it appeared you we don't store that much information but it's a little bit that's important but anyway otherwise it's the standard the image and the red actually in cold it's
coordinates in the y is encoded in the green energy and then the blue just of encodes the blending that will be necessary between the projector very simple uh which well I have found a way the plug-in we make for this is actually based on an excellent viewpoint and I extend the line I want to mention that this is an inner compass point but for thought of as it actually
worked well it's very easy that's pixel on the screen which is music on the projected it to figure out what color you are and what their companies will actually look in the look of people in the red green blue and with the red and green will figure the position on the desktop and just pick that color and then multiply that it was up to get the nice blending in that it is very simple there's no loss of is very efficient or you know that for every screen for every project now Father create the
lookup table well you could go to create just drawing the cost of coding the work really well that you need to align and there's . 2 which you can align by hand or you can align using the camera but the matter that help to make things simple for now we propose that if you have 2 projectors for management but basically fed through projectors you could try alignment by hand but you need a flat surface like this 1 here that the projected maneuver perfect which means no radial distortion but that's OK actually most predictor protein with that those lines you know must look like lines and then the projector is much they think they must be overlapping if there's no overlap the yard line by clicking on anyway you take on a few points and then the predicted will be a OK so our contribution here is the plug-in 1st but 2nd in this little side program of line that will make that hard work with them to just click on a few points Initial were so in practice
it's going to look like this where this is to reject that are overlapping and you're going to have a couple points out the gun and that's it it's going to be all you need to
get the distortions were not 1 last word about what's next them not since the the lookup table is an image you can use different ways created and so this is the simplest way but if you you happen to have a curved surface or where projector bouncing on curve never walk on all kinds of things that you can use a camera and so we will provided that the different programs for use in a camera up there but it will generate the same lookup tables is going to be the same income is flooded in the the thing work then that's pretty much where it had headed they not like this project right now is still working for the big set up but this is not something that is useful to that many people because you need to know 1st of all you need 7 or 8 Beijing projectors and of effects so we expect that this will be very the practical to make you know most computers that have to work you all put people to do work very simply multiple sold it for that and can now just to conclude
what I had to say about it so this is basically an attempt make Linux multi-projector more accessible users and it's really focused on simplicity and well the website to get the information on the web page that describe the whole thing tho is that you and that the much and then the work on the web cast of the not so this would it would conclude the little description but maybe will try to do an actual them so they just such as those what began as early we goes on to make
this work and I'm going to try to describe what we're doing so they can serve as a possible to lower the length of the of the of of
this but now what we have here is to HD projectors so there is no way to 1920 by 10 80 vectors then you know that they are overlapping and we've already set up the system so that that some of others at all he she starts flight just for the sake of it but we did all this just to be able to play the banking like course that's our goal as you can
see when you don't align projector you have a slight problem when you read overlap so anyway we're going to try to think that so well well what does that mean that much point in playing right now I guess but had anyway so will try to align this for you so it so the
1st step is to start the little aligner program
and it will light up the screen and the most important thing here is that the overlapping of the 2 projector is key you need or that and you go in the 1st screen and click on 4 points to make this who had just 4 points in the overlap and then you go to the 2nd screen and the cursor will turn into a little effects of on the right things that aren't then click again in the others being ignored up green non-green on top of red should yellow so I guess if you look yellower than it's pretty much aligned your goal to align the points the red and the green together then you can move by a tiny fraction of the pixel using the cat person is very easy thing when you start to see yellow everywhere they really happy means it's pretty much about to be aligned again like is that of a friend now the 2nd step the the last step is to define the whole screen area you want to use so you just click on the 4 points that define your screen that this thing and it will show you screen not now it's up to you if you want a perfectly square green well just measure from the ceiling or whatever but this is going to be your final grade again that kept maximizes every pixel images and once you're done you just the 1 of the key and this is where the keys are not super became so s for saying that it's going to be created to look up tables in your done with the alignment that's now all
that remains to be done is to get companies planning working and it's not already working like this now this is running you you want to our 10 11 . 0 4 the latest and you have to start companies by hand to get this C C P flag going it's a technical yet still trying to figure that that part but basically you start company the corporate then this is the option control of company is where you start and stop different plug-ins sold the plug is called like which is just enable and then you have to give them that in the to look up tables and 1 said it had to look up tables that created then you just sort of like in that that's the that's the 1 for the gamma parameter also trying to keep the number of parameters as low as possible because it's used bother when you have 20 sliders to adjust the OK I guess we're done we then that so when we're done just activate the plug-in just activated distortion rate and the look of the people and yet there you go so now let us mean and that's
that's really new time screen and that it does work so in the we also added some the using to be sure that you and I can wants align actually gets gets the distorted properly so now about the layer yeah let's maybe by a black OK so now actually
what this thing is that this game was meant to be played on the screen utilized the so there were following someone right local he's playing this problem so that the idea of the ID of another another another server meaning that you could find that the the most games well let me easy flag is nice it's going to go full screen there is that what most programs when you tell them to go full screen they don't go fullscreen legal fall that piece of the screen which is not always bring but this is something you will so anyway I guess how you can flag in there so I guess people are just not very active like and I guess the more will stop the but but you get the idea
for this and this is an open geonames work well some of it it's the show a couple more things to be useful for
those wanting that could there be interesting once you have a plugin like this it means that every program suddenly becomes multi-projector this means you can have it begins with a huge 4 thousand image at 1 to 1 ratio and drop it with the idea of going there in staple whatever all program and then the and this is what have is in there and noted that the will the solar really small them but this is this so again there is is no with that promotes 1 but they are OK so should be bigger but this this spilled it into integer thousand something and you will notice that although it very well aligned with the middle you might notice a slight change of color this is because the lapse of the vector are not the same but they're not the same page and also there's a lot of tricks that to align color perfectly OK and this is something will add but we don't want to that too much burden the 1st step in that the alignment the shows only when you have white you start with the
black image in the bottom of what has always been in movie plane is nice also that we we have a couple examples effectively we'll go full screen on the whole but on the whole display so this is an example it's it's a it's a little clip of anything we but as you can see that at the movie will just play right
away and we have the same you can play as high
resolution is want is going to work so this is a very nice way to get your whole movie theater going
on that was fine couple projected and the rest is is
by the way price projected going down very very quickly so this is becoming an alternative but we figured you know why not uh that used for the computers very nice is that a lot of shows open and that's the
following the we have another another it's basically at any program works on there but did not install that many previous 10 items on that most people you know still that's the sky open-source sky were
program in and this yeah this 1 does not full-screen by itself you have to actually make it
is being but what's nice here is that it's an actual guide you and then you get the full resolution of the of the sky and sanctions while 1st now it's a little it's the bottom of the the numerical directly from the button right there in come here and click on this yeah this and this and this new this stuff this and this also that this this is a true might die but we have some something like this but as you can see this in video program and the same you get really high resolution now there's so many programs can very very used actually the follow-up soul so the media I will just stop there and that there and you move around as far as stand there may be answered questions and that if you have any questions so on the the US otherwise well I guess that's already more or we don't there's something else mentioned that the code of course available so it's not as available as packages and stuff like that yet but still you can download the files and combined that very very simply so something it should work right away on um on the uh voiture yeah you can go to a webpage it is very front to browse the port of pixel line in that says that it's this deliberate the
Cemetery also groups note that this is what we used to look
like that flash forwards so anyway so essence under there all the instructions are there are lots of dependencies but it does that so in the future we really we integrate that somewhere instance become
perspective for the whole was so anyway so that's pretty much souls the uh thank you much and and future back very question will feel free to follow in the film and actually more which is quite common rather in question because I was just thinking about like we would like to assist and what it's done recently the the week that went through my big box store and they had nice projectors forward 900 dollars meaning home home theater projectors and when I went by my local target store on the clearance and kept they had a home gaming projected on clearance for 99 dollars paying more for a 2nd what can I do with that belong to this scenario and by way of course this most home computers that were you know more graphic cards were output
but you can buy also the video splitters like my trucks and armored trucks there's 1 you can have to work 3 strains of that laughter it's very feasible and there is so that the idea right the projectors prices are really going down so that the in the room not a question
and I was thinking about what is the future like with going to win the problem with the monitoring a piece that is something to be convenient so I'm thinking and like merging or on the grating cure of leading to something else to do all of Atlanta or something so we can actually working 3 of Florida because obviously we're going to move along and institutions for that's a really good question about because it's it's it's an excellent question about the in the the reducing the plugin you that if you moving on new feature that I think I mean I think this yet because it's kind of useful it would be nice to have an integrated so it's a pretty much seamless invite the following thing you know it should be natural this then also given that it's so means I have to mention that the having an open system likely explicit really easy to do that but it's not that easy that only on Windows or on my costs and so the question of what was the future with companies is I'm not sure about 1 thing I'm pretty much shorter is that on open GL effects on top of Windows will be there when we another in against year plug-in concept as as we need fooling itself is very useful so as long as that stays there were going to be moving this into whatever environment that becomes the right it can be rewritten very easily no problem that wishes that there had won the specimen wants to commence to to this last statement I think most of the dimension of the compass in dependent on come goes on on going to and so you can't you can't some and so on independent plug-ins this would be very useful to have 1 common formats of what happens at least 1 of which is the same thing you can other that's the so this should cover cave contents and the mountains of commands yes this problem that people can participate in that would be the it's a lot of work
and there is a lot of work for these things in the National movement In the Journal of the group and the few