Invisible paint? is it possible?

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Hi

is it possible(and exist for buying) invisible paint? such that with a camera and specific filter only i can see it?

i need it for outdoor, draw on a road like for example and be able to see it with the camera from about 500 meters ..

sry for my bad english.. thanks for help
 
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You might try something like

http://en.wikipedia.org/wiki/Luminous_paint" [Broken]

I'm not sure what degree of "invisibility" you can achieve and whether this is practical for outdoor conditions, but this seems to be the closest to what you're looking for.
 
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I don't know if it's possible, but I'm pretty sure it doesn't exist. Even the most "invisible" of luminous paints can easily be seen reflecting light and creating glare.
 
ok, not total invisible is ok too,

i just need a situation when using a camera(with some kind of filter, im not good understanding this field 2much..) i'll be able to
easily seperate it from the surrounding so based on image processing only(have no problem with that) i want to know if i see a specific pattern that i painted on the road or not

thanks for the help
 

berkeman

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Hi

is it possible(and exist for buying) invisible paint? such that with a camera and specific filter only i can see it?

i need it for outdoor, draw on a road like for example and be able to see it with the camera from about 500 meters ..

sry for my bad english.. thanks for help
ok, not total invisible is ok too,

i just need a situation when using a camera(with some kind of filter, im not good understanding this field 2much..) i'll be able to
easily seperate it from the surrounding so based on image processing only(have no problem with that) i want to know if i see a specific pattern that i painted on the road or not

thanks for the help
Are you familiar with how "Blue Screens" and similar work?

http://en.wikipedia.org/wiki/Chroma_key

A similar technology is used to draw the first down lines on TV screens for US football games...

As long as the people are not wearing the same color as the ground that they are standing on, you can use signal processing to tell where they are.
 
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There was a spray on a police TV show, which when sprayed on number plate prevented the ANPR (Automatic Number Plate Recognition) cameras from reading it (it showed up as blurry).

I thought it was quite clever, they pulled the guy over and booked him for it of course.

Not a clue how it works (or if it works that well), but perhaps a variation on that if you could find it? It's only visible (or noticeable) through cameras.

They sell it all over the net but I won't link because it's not strictly legal to use.

Mods, I'll let you decide on the validity of this post.
 

berkeman

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Mods, I'll let you decide on the validity of this post.
The similar thing I've seen is a plastic cover for the license plate that is not quite clear. It's supposed to work because the flash of the red-light-running-cameras reflects too much and obscures the plate information. Not sure what you would spray onto the plate to try to accomplish the same thing. In any case, the plate covers are illegal, and give PD officers a valid reason to pull you over for a conversation...

And I don't think whatever the spray is could help the OP. Seems like any "hidden" coloring of the ground needs to be in the IR or UV range, or of a uniform color that can be subtracted out by the image processing software.

I wonder what the OP is up too... ?
 

Borek

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Why not use some dye visible in UV only? If it works for bees and flowers, it should work - at least in principle - for OP.
 
thanks for help,

berkeman, i dont see how "Blue Screens" can help, i need exacly the opposite, situation where i can see sprayed marks on the road using the camera only and close to-invisible to human eyes
borek, we'll go to dye visible if we'll have no option, that why im asking it here :)

about the spray you mentioned, can you pm for example?
thank you all
 

Drakkith

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How about some kind of UV reflective paint or dye? I don't know if your camera could see it though.
 

Borek

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borek, we'll go to dye visible if we'll have no option
Visible in UV - that means ultraviolet, not visible to a naked eye.
 

berkeman

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berkeman, i dont see how "Blue Screens" can help, i need exacly the opposite, situation where i can see sprayed marks on the road using the camera only and close to-invisible to human eyes
The point of the blue screen technology is that the computer processing can recognize all pixels of the "special" color, and know that that pixel does not have anything covering it. That's why it needs to be a color that your people will not be wearing...
 

SteamKing

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Suppose you had invented invisible paint. How could you tell? It's invisible!
 

Drakkith

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DaveC426913

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The point of the blue screen technology is that the computer processing can recognize all pixels of the "special" color, a
But he wants it invisible to the human eye. Still don't see how a blue screen
accomplishes that.

I think we need more information from the OP. Why does it need to be invisible? Is it simply so that you can paint it on and conduct your experiments without attracting unwanted attention, say, by drivers, or even by the authorities for defacing roads?
 

berkeman

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But he wants it invisible to the human eye. Still don't see how a blue screen
accomplishes that.

I think we need more information from the OP. Why does it need to be invisible? Is it simply so that you can paint it on and conduct your experiments without attracting unwanted attention, say, by drivers, or even by the authorities for defacing roads?
Yeah, I'm assuming that the camera system has some sense of position via its fixed position and field of view, and can use color regognition to tell if the background/surface is occluded by something. Heck, paint the field pink!

EDIT -- Sorry, I'm assuming that the "invisible" means no cues to the folks standing on the painted area. If it's painted uniformly, and the position information is handled otherwise, then the position cues are "invisible".
 

DaveC426913

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Yeah, I'm assuming that the camera system has some sense of position via its fixed position and field of view, and can use color regognition to tell if the background/surface is occluded by something. Heck, paint the field pink!

EDIT -- Sorry, I'm assuming that the "invisible" means no cues to the folks standing on the painted area. If it's painted uniformly, and the position information is handled otherwise, then the position cues are "invisible".
You want him to paint the entire road pink?? I think the authorities would definitely have something to say about that.
...draw on a road like for example...
...a specific pattern that i painted on the road...
...sprayed marks on the road...
 

berkeman

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Okay, I missed that. I thought he was talking about a dedicated field. Still, you could make up an excuse for painting a stretch of road pink... Think breast cancer awareness or something...
 

DaveC426913

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Okay, I missed that. I thought he was talking about a dedicated field. Still, you could make up an excuse for painting a stretch of road pink... Think breast cancer awareness or something...
I think we have two very different ideas of what he's trying to do. I think he's trying to do this as discreetly and covertly as possible.
 

berkeman

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Hi

is it possible(and exist for buying) invisible paint? such that with a camera and specific filter only i can see it?

i need it for outdoor, draw on a road like for example and be able to see it with the camera from about 500 meters ..

sry for my bad english.. thanks for help
ok, not total invisible is ok too,

i just need a situation when using a camera(with some kind of filter, im not good understanding this field 2much..) i'll be able to
easily seperate it from the surrounding so based on image processing only(have no problem with that) i want to know if i see a specific pattern that i painted on the road or not

thanks for the help
thanks for help,

berkeman, i dont see how "Blue Screens" can help, i need exacly the opposite, situation where i can see sprayed marks on the road using the camera only and close to-invisible to human eyes
borek, we'll go to dye visible if we'll have no option, that why im asking it here :)

about the spray you mentioned, can you pm for example?
thank you all
I think we have two very different ideas of what he's trying to do. I think he's trying to do this as discreetly and covertly as possible.
Agreed. At this point, I'll wait to see if he comes back to claify his request. I still wonder what the heck his application is....
 
thanks again for the help,

i'll try to be more clear about what we doing,
we got some kind of field (my english isnt something..) outside, (mean outdoor conditions,day and night) and the field will be crowded by people,
i want to know(for some reason) if some specific zones(aprox half square meter) in the field are occupied or not using hanged camera only (i dont want put somekind of sensors everywhere..)

so i though about image processing solution, about the image processing algo i have no question, but about some material/color that as i asked,
i wanted to mark the special zones and filter them by the camera (i dont care about the quality of the images so any kind of filter, for example for UV spectcrum can be good if it does the trick)

the perfect solution for me will be some kind of color that wont attract much attention from the people..
the distance to the field from the camera will be like 500 meters max

borek, i'll check your suggestion, see if any shelf products exist for it(in normal prices..:) )
 
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You want to paint a field? A grass field? And then have people walk over it?

That's not going to last two minutes.

This seems like an awfully complex setup.
 

Ryan_m_b

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if some specific zones(aprox half square meter) in the field are occupied or not using hanged camera only (i dont want put somekind of sensors everywhere..)
Why not just visually check? If you are recording the scene just watch it back with a http://www.google.com/search?um=1&hl=en&biw=1366&bih=667&q=hand+counter&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi" to count the number of people that go into these areas?

Invisible paint and computer counting seems like an awfully complex and expensive way of doing things.
 
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DaveC426913

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OK, field is very different from road.

But more to the point: berkeman is correct: why bother painting anything on the actual ground when you can simply divide your image into its grid digitally?
 
oh sorry! (i told you my english sucks)
no field, yard, road like..
 
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