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What's that technology where they find hidden things from a 2D photo? Using radiosity, shadows, etc.


Domarius
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I heard, using a 2D photo of a book, they were able to extrapolate and render a playing card that was out of shot, from the reflection on the surface of the book.

 

Also you see this technology at the start of Will Smith movie "Enemy Of The State" where they rotate the virtual camera in the image taken from the security camera in the store, to see if there's something in the man's bag. There is a bulge, and the technician says that it could be a bulge, or it could be a shadow that their software mis-interpreted.

 

What's this technology called? Me and my brother wanted to read more about it and I figure someone here must know about that sort of thing.

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Yea that makes sense. I mean there's no way you can truly unblur a blurred out object in a photograph. I mean think about it. It all relates to the laws of science kind of like a physical to chemical change.

 

The way you know is if you can revert a change from one form to another then it's physical. (Example putting a mix of powdered juice with water, if you evaporate the water and leave the powder then you can bring back the juice by adding more water, so it's a physical change)

 

However for cooking, you can't go back to the raw egg, so it's a chemical change.

 

My point is that you can't go back some "magical" way to the object that is blurred out in a photograph. All the crap I've seen in CSI is impossible. There's no fucking way. It's probably all rendered in as stated above a theoretical way. Or whatever bits and pieces you can find like a blurred license plate, you try and come up with numerous numbers/letters and start your investigation there.

 

That's just what I think anyway, based on the education i've had. :mellow:

Edited by Unstoppable
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The way you know is if you can revert a change from one form to another then it's physical. ... However for cooking, you can't go back to the raw egg, so it's a chemical change.

 

Err, no. Whether a change is "physical" or "chemical" has nothing to do with whether it is reversible or not.

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I just saw some thing on "Attack of the Show" where Microsoft (I think) can recreate 3D models of popular places due to all the zillion photos from all angles available to automatically analyze and link together, interpolating the 3D information needed. It's real, though in infant status.

 

I found this link:

http://labs.live.com/photosynth/

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Err, no. Whether a change is "physical" or "chemical" has nothing to do with whether it is reversible or not.

 

Kool-aid juice can be turned back into the powder by simply boiling the water out of the powder. That is because the powder itself is absorbed by the water but is invisible to the naked eye. You'd have to put it under a microscope to see it. That's why it's a pyhsical change.

 

(Plus water probably has a lower boiling temperature than the powder)

 

A chemical change can't be turned back into a what it once was by physical means.

 

It has everything to do with being reversible because it can be proven.

Edited by Unstoppable
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I just saw some thing on "Attack of the Show" where Microsoft (I think) can recreate 3D models of popular places due to all the zillion photos from all angles available to automatically analyze and link together, interpolating the 3D information needed. It's real, though in infant status.

 

I found this link:

http://labs.live.com/photosynth/

 

That's interesting but the fact still remains. You can't unblur a blurred object from a photograph. You can only do estimates and such like I stated above of what the object could be. There's just no way, yet. Sure you can use bazillions of photographs but i'm talking about one photograph. There's no way to do it. Unless you could somehow go back int ime. :laugh:

Edited by Unstoppable
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NASA disagrees with you though, they work hard to find more detail in burred photos all the time

 

Detail does not constitute that they can unblur a blurred image. Can they find out what it was? Sure. Can they somehow take the photograph itself and turn it around, without any virtual or chemical change to unblurred status, no way in hell. Unless you can go back in time. For that you need a time machine, and be able to create worm holes. Goodluck Nasa. :laugh:

Edited by Unstoppable
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To put my point as simple as possible. There's no way you can change the actual blurred photograph itself in physical form (that you hold in your hands not on a monitor) to unblurred status.

 

What these programs do is generate a new photograph based on taking information from other photographs. That is impressive in itself. I hope you can understand now what I meant to say. :laugh:

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Kool-aid juice can be turned back into the powder by simply boiling the water out of the powder. That is because the powder itself is absorbed by the water but is invisible to the naked eye. You'd have to put it under a microscope to see it. That's why it's a pyhsical change.

 

Not disputed. I never claimed that physical changes don't exist.

 

A chemical change can't be turned back into a what it once was by physical means.

 

No, it can be turned back into what it once was by chemical means. There are reversible physical changes (boiling water), irreversible physical changes (pulverising rock), reversible chemical changes (oxidation of iron, can be reversed via the Thermite reaction) and irreversible chemical changes (combustion of propane).

 

"Chemical" versus "physical" has nothing whatsoever to do with "reversible" versus "irreversible."

 

It has everything to do with being reversible because it can be proven.

 

That doesn't even make sense.

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Maybe it was meant figuratively instead of literally?

A chemical change can't be turned back into a what it once was by physical means.

Smack a cake of trinitrotoluene and say that again. ;)

 

It's pretty much impossible to say anything is strictly physical or chemical, as both fields depend on each other to exist. Given enough energy and the means, any change can be reversed, and there are many examples of every kind.

 

All of this could have been avoided by just saying "you can't resolve data where none exists." :laugh:

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NASA disagrees with you though, they work hard to find more detail in burred photos all the time

 

I knew somebody will come up with this. :) If you refer, as an example, to the analysis of the Columbia crash, the situation is slightly different. The image was blurred, but they had other information as well, like speed and point of impact. Of course if you know some stuff about the blurred parts, you may be able to reconstruct it based on that knowledge. But you csimply can not unblurr an image if all you have is that blurred image itself.

 

If you get the blurred image of a serialkiller reflected in the shoppingwindow, there is no way you can determine the face from it by eleminating the noise. I saw this recently in a movie, but I don't take it seriously.

Gerhard

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I just saw some thing on "Attack of the Show" where Microsoft (I think) can recreate 3D models of popular places due to all the zillion photos from all angles available to automatically analyze and link together, interpolating the 3D information needed. It's real, though in infant status.

 

I found this link:

http://labs.live.com/photosynth/

 

I can't look at your links from work but are you possibly referring to Pictometry? I work for a mapping and aerial imagery company myself, though not in the pictomrtry division, and we're doing some of this stuff ourselves. Microsoft is one of our clients with their MSN virtual earth.

 

http://en.wikipedia.org/wiki/Pictometry Check this - it's not our company though. 3D models can be built from the 2D referance photography.

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If you get the blurred image of a serialkiller reflected in the shoppingwindow, there is no way you can determine the face from it by eleminating the noise. I saw this recently in a movie, but I don't take it seriously.

 

I used to very strongly agree with you, but I'm not so sure anymore from things I've read. It seems logically impossible I know, but maybe there's something more to it we don't understand. I always scoffed at those type of movie scenes, but I don't so much anymore.

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You can't create information that is not there. One thing is, that in digitial cameras the images are usually much higher resolution then you expect. I know this from my Minolta 300D, so this looks suprising sometimes. But if the information is not contained in the image, where should it come from?

Gerhard

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If you guys want to get into really hardcore "technology", the human eye has some pretty remarkable routines used to resolve blurry images. E.g., when light and dark areas are in proximity, retinal ganglions over-stimulate the light-side (looks even brighter) and inhibit the dark-side (looks even darker) so it creates an artificial, much cleaner contour at the intersection.

 

This is where you get this illusion, among dozens of others (the gray bar in the center is the same shade throughout, you can check by covering up the background).

 

Actually, it has all sorts of tricks to create clean, clear contours where none really exist, which illusions you've probably already seen ad nauseum.

 

You can't create information that is not there.

 

This really isn't giving enough credit to Bayesian statistical methods. You definately can posit information that isn't there to resolve signals from noise based on certain assumptions of statistical likelihood, such as shapes and gradients are relatively contiguous and uniform throughout, bound by relatively smooth contours (not the coast of Norway), etc. These methods are at the heart and soul of a lot of signal recognition stuff.

 

I mean, it's not literally "creating" the information, it's just positing it based on previous experience (the true source of the information). But even this can go a long way ... although it has its limits. If you have a valid criticism, it's that the statistics can only go so far in reading information into the noise ... too little signal information or too much noise and it just can't cope, or the statistics just aren't powerful enough. If the blurry photo can't resolve the killer's face in the window, it's probably a problem of degree of hardness, not type of problem, IMO (I guess it depends on the situation).

Edited by demagogue

What do you see when you turn out the light? I can't tell you but I know that it's mine.

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A chemical change can't be turned back into a what it once was by physical means.

Sure it can. Chemical reactions are equilibria that can go either way based on external conditions. Take for example an exothermic reaction:

 

Chem1 <-> Chem2 + Heat

 

It's energetically favorable at room temperature that Chem1 turns into Chem2 plus heat. Add heat to Chem2 though, and you can make the reaction go the other way. There might be other things involved in the reaction that are assumed to be around in abundance, like water or oxygen. Same goes with redox reactions and applying voltage.

 

I don't have a lot of experience going around labeling things as chemical vs. physical changes. Chemistry is really just the physics of chemical bonds IMO, so it's all physical changes :). If I had to make a simple definition though, I'd say that if chemical bonds are being formed or broken, it's a chemical change.

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You can't create information that is not there. One thing is, that in digitial cameras the images are usually much higher resolution then you expect. I know this from my Minolta 300D, so this looks suprising sometimes. But if the information is not contained in the image, where should it come from?

An early episode of CSI: New York featured the team solving a crime by enhancing the image of the killer's face...from the reflection in the pupil of a nearby sleepwalker...who had been caught on a low resolution, low framerate, black & white security camera. I will now defer to the expert opinion of Morbo:

 

 

 

morbo.jpg

SECURITY CAMERAS DO NOT WORK THAT WAY!

 

Thank you, Morbo.

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If you knew it was a playing card it wouldn't be so bad; playing cards have a very standard format. You could probably count a few of the symbols on it, noting their colour and position and using this information to take an informed guess at which card it was. (Though differentiating clubs and spades might be tricky.) You couldn't use the same technique to "unblur" a face though.

My games | Public Service Announcement: TDM is not set in the Thief universe. The city in which it takes place is not the City from Thief. The player character is not called Garrett. Any person who contradicts these facts will be subjected to disapproving stares.
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