Video in TIB AV-Portal: HoloPov:

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A program for predicting image geometry in display holograms
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HoloPov: a program for predicting image geometry in display holograms
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In display holography, when the reconstruction wavelength or geometry differ from those of recording, the image is, in general, distorted and aberrated. These variations from the original object are hard to predict using the usual optical equations, which are best suited to imaging systems where the pupil of the system is known a priori. Here I describe the latest features of a computer program (HoloPov) developed to predict and to graphically display the distortions and aberrations in display holograms. The program has an easy to use graphical user interface, and can produce animations.
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but could but right I just put this paper and to some people are not just the microphone guy here but of the something of interest for when name's discovered again what we have to OK see on the video they don't know spoil so I might do that again that's felt quite OK sit down at I will graph adult or is my side as my day job is to evaluate technologies in in publishing and typesetting and quick plug for for longer for adult or gets nonprofit it's just a place for log refers to put any contributions in the papers that we think will be of interest to other demographers um so whatever you have if you think it's of interest it's not doesn't have to be a paper can be of anything that other people here might use standard if it is useful on making decisions we will clean it up will edited the typeset put online of it like the conference so what is it we we would like to have any contributions incidentally it I think you all know part is doing a fantastic blog of this conference and its online everyone's following it and if you get all over the world or there's a link straight to the yeah the number OK whole call is is a program that I've been talking about food for predicting how an image look that's just the Duke it's the Einstein his upstate should have changed it shouldn't what's the problem the problem looking at these you make a hollow ground with 1 wavelength 1 set of geometrical parameters then you replay say you made with green here played with the red the image is in a different position it's a it's distorted etc. now we all know that but I didn't find a good program at an easy program to show me to predict a pre visualize what I'm going to get all suppose I want to have a rectangle the particular position what do I have to do to the to the 1st that the written recording stage to get what I want in the reconstruction the 3 important things to realize if if when we make a lot of ground and then reconstructed with with with different parameters 1 is what I call the moving to pull this is very unique and holography this is already made with green green lights and we're reconstructing now with a different wavelength mammalian animation heading between blue from blue to red and as you can see obviously the image changes position you can see that OK as you know that there's geometrical distortions and that thing to notice is that the for any wavelength is looking through different parts of the hollow-gram it's not through the same pot that generally an optical systems the that he did the pupil or the center of all way way where the the the line looks through an optical system is fixed so if you have a ray tracing program say for lens design they assume that your eyes in this position the points to the center than there are all kinds of questions now in pornography it's more difficult because the pupil is moving depending on where you want your freedom that's 1 thing 2nd thing is that gender in general the images distorted distorted means distorted means the point is that is not at the same position as it was so this distortion does the moving people and that is what this aberration every problem of aberration but really all aberration means is that if you look at an image from different positions they it doesn't seem to be in the same same position from different viewing angles this is that when you have generally when you have that sort of usual swing that you have an an image that is because of elaboration the mangled champagne 96 67 wrote the paper and it was the 1st paper that allowed the 1st set of equations that allow you to work out from the the uh recording parameters giving it say the wavelength of distance from the reference beam object etc. and then you you go to the bar the reconstruction parameters would tell you exactly what the image would be and what the aberration will be at that point so how much swing there would be around the point is in have the that is that the the fundamentally is very very a simple elegant equations so it actually predicts the position and the aberrations but it assumes that the pupil just like any optical system it assumes that when you're looking through the center of the play place this is the this is the problem so what terms that's that's the fundamental problem what we have to do I won't go into the details but you know that you not always be looking you only looking through the center the hollow-gram so what you have to do is to make a guess of where that people might be and use Newton's approximation to get to the actual position and but that works quite well about 3 or 4 iterations and you know exactly where you looking through so we need a program to plug in these equations and then shows what we get which program that we used so I think we have to do what is calculated image position from the all the parameters secondly we need to display graphically good so I spent a long time thinking which program you I use and not really a program the different programs and then of course you get the output set of numbers you put it somewhere else to get to get graphics you definitely want a graph here I really want to get an intuitive feel what the images going to look like before I make I found really fantastic grammatical and that really deserves applause of raise if you haven't heard the call rate please to polveri or anyone interested in graphics playing around if you want to learn programming this is I believe this is probably the best the program to to learn so I'll give you that very quick to so it's a 3 D rendering program OK and it takes the difference is normally you have things like 3 D Studio Max and what have you I don't I don't really know this but the modeling is interactive you draw a sphere hand you you you draw a rectangle you look different places for the like here such a interactive then you get an image the difference is that it's actually you have to write the text as a programming language to write program press a button and it gives you the output Janet now mostly computer 3 people they just ignore that thing on this some the key thing because they want to work interactively but certain things you can't work interactive and for here I find that it's really a perfect perfect thing for fall from my application here as a full programming language to surrender but it's a full programming language to with a very nice clean syntax how the pole right had does the renderer work basically you have you ever seen you have to define a seniors have a sphere the of the of cone here etc. the reflect the surface color is this or that you have to have a light source of the ways you can see you need a cab you need to take away your cameras is the 3 things you need to create a scene OK in a physical sense creates singleton in the ball rolling things but how you get quick very quick 1 minute
demo and don't be afraid of this code if you not programmers this is just just just look at what's happening we're declaring declare a camera location is an X Y that system in 0 0 minus 20 on the more about which is which but just if it works it's declaring a sphere location is at the origin 0 0 0 sphere radius of 1 . 5 the texture has a pigment which color ones in that even the color is red green that goes from 0 to 1 to go you've got red green really so that's going beyond light sources at this point color of the light source is 1 1 1 which is quite camera location is here etc. angle of the camera is 1 and the only up to that's a camera that's a light source and we have a sphere is a very simple there so we rendered that's what we get so I can go back here and change the color so the red green that just make it ready so that 0 becomes red and camera it's a moment in knowledge that that make it 10 degrees so it's a narrower angle OK
and there's lots you can you can add a light on the other side is at the moment like this coming from here I can uh picture this here copy that I had a sphere texts have another sphere text I just don't want to go to follow this because I get themselves into trouble and say this is yellow knowledge sources that can and position and let's have another sphere this time with the 2nd texture um that's not the sphere location we had before but sphere location you can just add and say 3 in the x direction 0 0 I
hope this works this is also things are going to go wrong here it has worked and you can't see it because it's behind something else believe me this stuff the outcomes governors of the drug already right but the latter maybe some of you itu-t said it's enough and so what why is should yeah well
you know the and you can see I'm reversed this OK um but let's forget that so sphere radius
is now so of point 5 would make it to so that to become a bigger that's probably considered it works so there is the same point from this point to that point radius this color that such a not just to show you what amazing thing people in case you think find clever
we look at some seriously this is what people are doing the this is line by line you got incredible results actually this despite its this is not this type of road some subroutines to draw optics they can see you that's a lens made from 2 spheres you cut 2 spheres wouldn't together you save made of glass refractive index this that's a mirror refractivity 1 1 of them the concave mirror subjects and the like you can say it's sort of translucent but not quite once you've done that you just write the lighting of brawl mine laser from here to there but this is what a clever guy sitting that is text right it's really really useful this is a very very famous guys you single so or you yeah this is so I just want to quickly show that you if you ball real told anyone animation image is a text is no interactivity about the beauty of text is if you want to change something you just changed 1 parameter changes right and you can automate generation etc. OK so that's polveri that's public so I thought I'd I'd started with this and and in the end it's it's it's a started working quite well of course
the whole for obvious reasons the other thing I've done actually I've put them at the sort of the front-end this is a thing called revolution if anyone's it uh and familiar with high in the early days of wonderful program HyperCard I'm sure you are the worst thing Apple ever did was to kill HyperCard they should not be forgiven for it as a really was the 1st scripting language had anywhere been looking for a hypergolic placement 20 years and a few years ago this came at the school revolution and its cross-platform etc. and so what I've done is a have a we can cover quick look at the main file you can see that this is you know declare object grid true image it's a huge program you calling and things but you don't want to edit the to the text of what I've done is I've put a as sort of this graphical front end here which rights they configuration file of all object distance object and that such a enough to look at the code so I give you a demo with the breath OK let's say let's run this to begin with is running this it's a batch mix process in the background but you just see the doesn't that doesn't do anything but what we got here we have an object that's what the object now these things are divided the so you can click on this and so we have an object here that the 2 units of weight is our objects this green points here 2 units away angle above horizon etc. etc. just leave it there is that the size of the object is 0 0 0 so it's just the point recording geometry it's reference beam is 100 units away 45 degrees above horizon wavelength 550 reconstruction hundreds 35 degrees this time and it's um 600 so that's what the so if we change our object to something more interesting now instead if I put 1 here 1 and 1 we get a q that every time I put something it'll just start from scratch it's an immediate mode immediate means don't wait for me just do it so that's here you go the reason you got those thoughts is that I've said in figure 2 what to draw I've said put the object as points discussed is green points uh but no object great but by 1 images point you could have object great instead of points OK so it'll do the same thing then you got really really depends what you want to look at you can ask so that's green and that's what you get here we can say well let's go to the observer suppose the observer these at the moment is minus 5 doesn't this evil looking I here is 1 of the 2 eyes and it said angle above horizon is there and decide these 0 I put the minus 45 so the to decide which of the world looks like from the OK so that's and what else can we do in the object I can say at the moment is a great so it is joined these points of the grid separation is once you get just secure Fox 8 . 5 then it put an extra set of in between so you can see more clearly what's going on and was and here because that H 2 white college the fact that that the horror and that's reconstructing the did that so even if there's no h 1 right it actually works this way if that even if it was a single the hurricane the final grammar and let's assume that this is I'm just just shooting from the hip here as it were and lets the distance let's make it 0 so the average distance of the object from the plate 0 that means it's going to be like an image plane the so you can see that that's now I put this on low resolution by the way the courts of it's quick at camera settings you can choose what resolution so if if that were 800 it's just takes a bit longer to to do I just want to know but if you don't stop 0 dispersion going on the reconstruction this 1 here yes it it the it's it's it's falling off the side this should say dispersion compensation those a test and the people's thank you all put this on what that those that I need reminders like that so that I can say I can decide what to do next um right let's click on dispersion compensation what that does it says right I don't care what reconstruction angle you told me I'm going to change the angle so that there's no this dispersion of the sentence the so it's moved then rate up so that the you see so so you're looking at so that any point that will axis its own again OK yeah automatically overrides this value 35 yeah so if I put that 700 right the it should not come at the steeper angle so that you still get the course yeah so now you can see that
things that's what happens with dispersion compensation you go the you've got there's no lateral dispersion but there is no to this a sort of a squashing effect they might say well what you are interested in is this back the back face you wanted to be near where it was before OK so that means that the weight just intuitively I think it's my recording reference being if it was closer than as you Paul the reference away that should corrected so I'm just going to guess put 20 here so I'm recording with the shorter reference being so that when the comes along the backtrace goes back a bit and that's can happened its neck cases the other office reconstruction sorry this reconstruction so it's a recording I want to change change that to 20 so again that was doing you don't lose pushing it for that that is close OK if you make it 10 it's going around yeah it's coming in little bit closer but then you get the magnification now you've got the back of the getting bigger the fund is getting smaller does that make sense that in that's that's what happens if front come over yeah so but this back to 100 as well as you go we've got here but I'm going to put this on the late so that it doesn't everytime I change something it doesn't run in the back and you want change several things then that's better and supposing you got and H 1 now I so this is going to very very tough because of going you know how you manage 100 actually it's it's simple all you do is you put an age 1 you put for the 4 corners all of it as part of the object and then any this distortion you just move those you just do the the the the geometrical distortions on those and you can see with the age 1 of so supposing your each 1 at the moment there is an H 1 but it's not visible so it doesn't show it to you so that's that's make H 1 visible spectrum OK so that's your each 1 of put the the observer by on 0 room too much difference apart from the fact that you see use which ones and the I don't want to draw let's get rid of the object so we just see the image so that's just the image and you can see it's that's it so the pushed together which which is what we want get it still a dispersion compensation um what should we do right let's take h 1 and this single vineyards image at the moment if you if you observe if I put that observer at 45 degrees it still shows me the image but actually wouldn't it from them because H 1 there is no which 1 if I put being its image that is it will only show the image when it's visible through that portal right that's OK because you're looking through the if I say the observer nice going to say uh 30 degrees you may get some of the image now being not being dissolved all of it has not been visible so if I put minus 20 should be allowed to some to some of the emission of the scarce natural number 24 and in practice the enough to show when I cook before 1 of them is like it's a 24 doesn't the it it doesn't have to just assumed you don't 1 i in the center of OK so that's just so you can see from here you can see and half that part of the image is visible and that what is yeah because that each 1 now you can do and animation here with animation you can see get an idea of where where it goes now I also have provided with h H 1 just to see what's going on because they showed linear just an idea lecture show you like to parents off the divorce through which you would see the image the OK now it's that's very close to that but you can see it's growing at sort of combed through the center of between the eyes right and estate if the eye goes back a bit further you observe the use state minus 10 yeah it's it's so so you can see that this plane here there's sort of long triangle that is cutting through the the image that you also yet at the moment I can't but that term I have I have got in the interactive thing I can go in I can go into the the following you mean the viewing position you the problem I can do 1 of the time what I haven't done is implemented that in the graphical interface I have to go in and if I go into the main far there's a camera
here in Canada I can say camera today at the moment you got communication is what I call camera perspective Pfizer camera left and if I his camera lens best switch off the perspective but you can choose perspective on not so that'll give you the left hand side it works yeah so that's looking from the left you can you can see the common well so I got here and just get rid of that in units in each on In unit in its image that's been yet but it's not visible I think what I'll do is because I'm so if you look quite relaxed so here for I can
give you 1 that i've to cooked before look this is where you change the reconstruction being light injury animation that the I put to any things in here so if lot them there are 2 things that I have a new 1 is multi-image image you can't take anything for example you can say I want the observer to be at 0 but give me multiple images with an empty the 40 45 degrees and give me 10 of them and all we superimpose on the same image you can say I want my objects to be multi image and say rotating around the center of the H 2 so you get on top of that we have animation you can say 0 1 and animate this which so many frames and and change this parameter right so that rather than the life tree what it does so this is as he is normal so the distortion that you get this is that the usual swing this is the aberrations get so here you can you can have an idea of what it looked like after you know once you made on this is the same image but the dispersion compensation it shows you there's there's obviously is that the dispersion is gone so it's gone back to the center it's actually and you can see that the that the distortion is less as well sorry the the aberrations that swings around much less so the special compensation either is a good thing to to use same thing this time with animation and with multi image this making multiple images but used that the wavelengths around the center weight so you've made a hollow-gram of acute your reconstructing with white light and this is what you get what you get is dispersed in the time yes this is the the this what you see here these arrays all um just binds to the center of each image right so you that's that's you know you can forget but this is the blurring exactly that's exactly the spectral learning the same thing with dispersion compensation so automatically compensating for this version just as if you have a diffraction grating before so you can see that only the longitudinal dispersion this is this is that this is a mark with again multi-image but the images you got 50 images going so if you have to make an image suppose you you say all I want to state that I want to look from this position on my final hollow-gram 659 it to have to be precisely and all you can work out what the shape it should be before you make here put the camera with the audience single more realistic picture of what you get and this is you got the meeting on here so it doesn't show you the image if it's going off the and he has been getting is on H 2 not under this 1 but you can but linear thing on H 1 and H 2 so you can see where the cuts off when each 1 is cutting questions cutting this is a nice this is an this is image with the different wavelengths with within each 1 so you got to disperse H 1 that here this is a full of the image plane full aperture you can see in the plane its shop always done here but from the magnet gets more and more blurred and gets distorted and as you get to the top and bottom you get this color fringing because you can only see through the rules for the red mosque same thing this time having in Maryland each 1 this is a a so the H 1 is now much narrower so from any position you can see through 1 wavelength or or a narrow bandwidth again you get all the dispersion of this distortion you get same thing now animating the always moving in and out so you can see when the I moved here you get your green and no this this distortion secure and as you go back and forth to get the usual stuff that the thank you positive vote of confidence from my good friends with instilling mean and I want a bigger prosody and is a real 1 Figure to impress utilized I want you to think this this is estimating the height of each 1 OK and you can see it's going from full aperture to render so you can animate anything you like animate the whatever parameter changes you can put and 1 thing that's it except to say the software is still um mean that it's you I'm not the real programmers so it's not in a in a in a state to say well this is finished but it's a bit flaky anyone wants I'm happy to give you it's it's free of charge operates free and this but that's the thing I've written that's free and lgpl so it's it's open and free and that the at the interface revolution is not free to to to create things but it's free to actually to run so that's available as well so if you want I can send you that and do you know it's the time of the year what was I going to of 1 you this is 1 of there might and this is right the yes this anyway I can but anyway that's including an infrared at the moment I have that as a uh what it does automatically it takes the wavelength and it give makes that the color and the brightness that it would be so as you get toward the 798 as it becomes darkened opposite 750 you wouldn't see any of the that but you can change that to show you you can switch that that's just the thing it's so intuitive thing but the it's just the same equation yeah we can show on the following it's often charts it's on previous slide is on the it's on the number of . 0 this 1 for you you all no threat there's no there's no cost fiction so it's only the PLC compost to this is the 1 who I the the last thing I also to use all and you will look like this 1 that 1 of the world so if there is a lawsuit thing I guys and the the and what yeah yeah if if you if you send it all you know I think we should well had some kind of structure to it so that you know be you something of database you know the me and my big mouth when the the banker this