I've been kicking around this idea recently, and I think it just might work. The idea is for a camera that takes pictures with sound instead of light. If you have to ask "Why?" then you don't need one, and you may be on the wrong website! ;) I just think it would be fascinating to play with.
Most light cameras use a lens, but the simplest way to focus the incoming wavefronts onto your pixel array is with a pinhole. The pinhole can be almost any material that is opaque to light at around 550 nm wavelength. The sound equivalent might be some type of sound-deadening baffle, maybe a slab of drywall, or cardboard, or other insulating board. For light, the pinhole is often literally a hole made with a pin, but for sound the wavelengths are many orders of magnitude larger, and so everything has to get correspondingly bigger. For example if our acoustic camera were tuned to pick up roughly 10 kHz audio (wavelength in air is about 1.3 inches), if we had just 32x32 pixels at 1 wavelength pitch, the pixel array would be nearly 4 feet on a side. For a focal length of 2 meters (79 inches) the pinhole would be about 20 inches in diameter, for a 30 degree field of view. Potentially you could capture these low-res images and mosaic a bunch of them together for a much larger image.
That's all well and good, but 32x32 pixels means you need 1024 total microphones! Even if they cost 50 cents a piece (less than the cheapest mic on DigiKey) and could solder each one in 10 seconds, it would cost over $1000 and take 3 hours of soldering just for the mics! Plus you might need an amp for each one, some number of ADCs, some way to pull all that data together, etc. So here's what I'm thinking: you make the imaging array out of large PCB panels that you etch yourself, and you build the mics in yourself as part of it. I'm leaning towards homebrew condenser microphones using aluminum foil as the diaphragm. You'd need to develop a good way to make an array of these mics yourself but it seems doable to me. Here's a page showing one guy's own homebrew condenser microphone, clearly not streamlined to be made hundreds at a time, but still. I think with some experimentation you could get a system down for making 100 mics on a panel in just a few minutes.
I think with the right mic design, you could multiplex them all together using just two inexpensive mux ICs, a single amp, and a single ADC. It would probably take several seconds to capture each image since you'd only be pulling in one pixel at a time, but the processing would be really simple. You could even do an FFT and extract out different frequencies to be displayed in different colors. Different materials would show up in different colors. Practical? No way! It would sure make some cool pictures though.
This is a very cool idea! It sounds totally magical, and I would love to see what thos pocs will look like-- Too cool!!!!
I do have one concern -- like a light camera, which is black on the inside, the bellows of your camera will need to be anechoic, and that might be the most challenging part. Doable but possibly very expensive for fancy foam panels.
On Oct 6, 2012, at 10:38 PM, Dave <dgsh...@gmail.com> wrote:
> I've been kicking around this idea recently, and I think it just might work. The idea is for a camera that takes pictures with sound instead of light. If you have to ask "Why?" then you don't need one, and you may be on the wrong website! ;) I just think it would be fascinating to play with.
> Most light cameras use a lens, but the simplest way to focus the incoming wavefronts onto your pixel array is with a pinhole. The pinhole can be almost any material that is opaque to light at around 550 nm wavelength. The sound equivalent might be some type of sound-deadening baffle, maybe a slab of drywall, or cardboard, or other insulating board. For light, the pinhole is often literally a hole made with a pin, but for sound the wavelengths are many orders of magnitude larger, and so everything has to get correspondingly bigger. For example if our acoustic camera were tuned to pick up roughly 10 kHz audio (wavelength in air is about 1.3 inches), if we had just 32x32 pixels at 1 wavelength pitch, the pixel array would be nearly 4 feet on a side. For a focal length of 2 meters (79 inches) the pinhole would be about 20 inches in diameter, for a 30 degree field of view. Potentially you could capture these low-res images and mosaic a bunch of them together for a much larger image.
> That's all well and good, but 32x32 pixels means you need 1024 total microphones! Even if they cost 50 cents a piece (less than the cheapest mic on DigiKey) and could solder each one in 10 seconds, it would cost over $1000 and take 3 hours of soldering just for the mics! Plus you might need an amp for each one, some number of ADCs, some way to pull all that data together, etc. So here's what I'm thinking: you make the imaging array out of large PCB panels that you etch yourself, and you build the mics in yourself as part of it. I'm leaning towards homebrew condenser microphones using aluminum foil as the diaphragm. You'd need to develop a good way to make an array of these mics yourself but it seems doable to me. Here's a page showing one guy's own homebrew condenser microphone, clearly not streamlined to be made hundreds at a time, but still. I think with some experimentation you could get a system down for making 100 mics on a panel in just a few minutes.
> I think with the right mic design, you could multiplex them all together using just two inexpensive mux ICs, a single amp, and a single ADC. It would probably take several seconds to capture each image since you'd only be pulling in one pixel at a time, but the processing would be really simple. You could even do an FFT and extract out different frequencies to be displayed in different colors. Different materials would show up in different colors. Practical? No way! It would sure make some cool pictures though.
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I should imagine that you can make an array by: - etching "condenser plate" zones on a pcb (hexagons might be nice in practice and for symbolic purposes) - printing a "grille" over the PCB substrate that outlines each condenser plate -- the reprap would be ideal for printing the grille - spread adhesive on the grille and lay foil on it (gold or copper leaf might make a nice, responsive membrane)
With some clever layout, you should be able to run traces that multiplex access to the sensors.
I think that there is one major difference between traditional light imaging acoustic imaging -- you can easily generate coherent "illumination" with sound and can easily measure phase differences between acoustic sensors. As a result, you have much more information available. I kind of wonder it it's possible to use phased array principles to make multiple, synthetic apertures and then use something like polydioptric imaging techniques to make "sound-field" cameras that can post-process images to play with focus, "look-angle" etc. You should be able to dispense with "lenses" and "housings" -- you just need that array (and lots' of fancy math).
On Saturday, October 6, 2012 11:49:03 PM UTC-4, Jack Zylkin wrote:
> This is a very cool idea! It sounds totally magical, and I would love to > see what thos pocs will look like-- Too cool!!!!
> I do have one concern -- like a light camera, which is black on the > inside, the bellows of your camera will need to be anechoic, and that might > be the most challenging part. Doable but possibly very expensive for fancy > foam panels.
> On Oct 6, 2012, at 10:38 PM, Dave <dgs...@gmail.com <javascript:>> wrote:
> I've been kicking around this idea recently, and I think it just might > work. The idea is for a camera that takes pictures with sound instead of > light. If you have to ask "Why?" then you don't need one, and you may be on > the wrong website! ;) I just think it would be fascinating to play with.
> Most light cameras use a lens, but the simplest way to focus the incoming > wavefronts onto your pixel array is with a pinhole. The pinhole can be > almost any material that is opaque to light at around 550 nm wavelength. > The sound equivalent might be some type of sound-deadening baffle, maybe a > slab of drywall, or cardboard, or other insulating board. For light, the > pinhole is often literally a hole made with a pin, but for sound the > wavelengths are many orders of magnitude larger, and so everything has to > get correspondingly bigger. For example if our acoustic camera were tuned > to pick up roughly 10 kHz audio (wavelength in air is about 1.3 inches), if > we had just 32x32 pixels at 1 wavelength pitch, the pixel array would be > nearly 4 feet on a side. For a focal length of 2 meters (79 inches) the > pinhole would be about 20 inches in diameter, for a 30 degree field of > view. Potentially you could capture these low-res images and mosaic a bunch > of them together for a much larger image.
> That's all well and good, but 32x32 pixels means you need 1024 total > microphones! Even if they cost 50 cents a piece (less than the cheapest mic > on DigiKey) and could solder each one in 10 seconds, it would cost over > $1000 and take 3 hours of soldering just for the mics! Plus you might need > an amp for each one, some number of ADCs, some way to pull all that data > together, etc. So here's what I'm thinking: you make the imaging array out > of large PCB panels that you etch yourself, and you build the mics in > yourself as part of it. I'm leaning towards homebrew condenser microphones > using aluminum foil as the diaphragm. You'd need to develop a good way to > make an array of these mics yourself but it seems doable to me. Here's a > page showing one guy's own homebrew condenser microphone, clearly not > streamlined to be made hundreds at a time, but still. I think with some > experimentation you could get a system down for making 100 mics on a panel > in just a few minutes.
> I think with the right mic design, you could multiplex them all together > using just two inexpensive mux ICs, a single amp, and a single ADC. It > would probably take several seconds to capture each image since you'd only > be pulling in one pixel at a time, but the processing would be really > simple. You could even do an FFT and extract out different frequencies to > be displayed in different colors. Different materials would show up in > different colors. Practical? No way! It would sure make some cool pictures > though.
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I'm really curious as to the images this will produce. From what I understand, sounds scatters much more than light. It influences the air of the room, mixing and creating some chaos in the airflow. Focusing.an image of that would be.... Difficult. Akin to taking a regular photograph, but in a foggy room. Except also the fog interacts with itself. I'd also be curious as to how the "focusing" effect would change. It normal photography, as the lens is moved from the photo sensitive material, it changes the distance of focus. Sometimes, since lights different colors are different wavelengths, you get different colors focusing.differently. its called.chromatic.aberation. Since sounds wavelengths are so much larger, does that mean we'll be effectively tuning out whole parts of the audio wavelengths?
I'm really curious as to the images this will produce. From what I understand, sounds scatters much more than light. It influences the air of the room, mixing and creating some chaos in the airflow. Focusing.an image of that would be.... Difficult. Akin to taking a regular photograph, but in a foggy room. Except also the fog interacts with itself. I'd also be curious as to how the "focusing" effect would change. It normal photography, as the lens is moved from the photo sensitive material, it changes the distance of focus. Sometimes, since lights different colors are different wavelengths, you get different colors focusing.differently. its called.chromatic.aberation. Since sounds wavelengths are so much larger, does that mean we'll be effectively tuning out whole parts of the audio wavelengths?
> I'm really curious as to the images this will produce. From what I
> understand, sounds scatters much more than light. It influences the air of
> the room, mixing and creating some chaos in the airflow. Focusing.an image
> of that would be.... Difficult. Akin to taking a regular photograph, but in
> a foggy room. Except also the fog interacts with itself. I'd also be
> curious as to how the "focusing" effect would change. It normal
> photography, as the lens is moved from the photo sensitive material, it
> changes the distance of focus. Sometimes, since lights different colors are
> different wavelengths, you get different colors focusing.differently. its
> called.chromatic.aberation. Since sounds wavelengths are so much larger,
> does that mean we'll be effectively tuning out whole parts of the audio
> wavelengths?
> --
> To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to
> hive76-discussion+unsubscribe@googlegroups.com
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> http://groups.google.com/group/hive76-discussion?hl=en
Sound is direct enough to allow bats to navigate by it in the night. Sonar
and ultrasound are types of acoustic imaging, and these days can make some
very detailed pictures. So I have no doubt this can be done.
The implications for 3d imaging are kind of exciting. The Xbox Kinect does
it's depth sensing with infrared light, presuming that brighter pixels are
closer pixels. Of course, put something that is very infrared-reflective in
the scene and it breaks that assumption. With sound, it's slow enough that
you could clock the amount of time it takes to bounce off of things,
triangulate the bounces, and come up with a 3d picture.
Let me know if you get around to working on this, would definitely like to
help.
On Sunday, October 7, 2012, Joshua D. Johnson wrote:
> I'd like to hear Brendans take on this. From what I understand light
> travels in a fairly direct line while sound doesn't.
> Maybe an ultrasonic emitter and all the collectors on a concave surface?
> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <kyleyankan...@gmail.com<javascript:_e({}, 'cvml', 'kyleyankan...@gmail.com');>>
> wrote:
>> I'm really curious as to the images this will produce. From what I
>> understand, sounds scatters much more than light. It influences the air of
>> the room, mixing and creating some chaos in the airflow. Focusing.an image
>> of that would be.... Difficult. Akin to taking a regular photograph, but in
>> a foggy room. Except also the fog interacts with itself. I'd also be
>> curious as to how the "focusing" effect would change. It normal
>> photography, as the lens is moved from the photo sensitive material, it
>> changes the distance of focus. Sometimes, since lights different colors are
>> different wavelengths, you get different colors focusing.differently. its
>> called.chromatic.aberation. Since sounds wavelengths are so much larger,
>> does that mean we'll be effectively tuning out whole parts of the audio
>> wavelengths?
>> --
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>> To unsubscribe send email to
>> hive76-discussion+unsubscribe@googlegroups.com <javascript:_e({},
>> 'cvml', 'hive76-discussion%2Bunsubscribe@googlegroups.com');>
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> To post to this group, send email to hive76-discussion@googlegroups.com<javascript:_e({}, 'cvml', 'hive76-discussion@googlegroups.com');>
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Jack: I think you could get away without worrying about it, but something like egg cartons would probably help a lot and be dirt cheap.
Pez: totally, phased arrays would be awesome. You'd need at least like 4x4 sensors (more would be better) so you'd need like 16 good ADCs that are simultaneous, not multiplexed, and a processor capable of pulling all that in and at least storing it in realtime. The processing is actually fairly straightforward once you have the hardware and the RAM for it. One nice thing about the pinhole camera idea is that you can switch out the mics to sense other things: thermopiles for a crude thermal camera, antennas for a microwave camera (think passive radar where the scene is illuminated by every wifi router and laptop in the building), etc. Also I believe that lots of the characteristic image artifacts and ambiguities that show up in phased array images (like weather radar, ultrasound, etc) would go away. Absolutely I'd love to work on either one though, and that's part of my motivation to look into FPGAs.
Kyle/Josh: waves are waves, they all act the same. Yes, the images would be strange compared to visible light. Visible light's tiny wavelengths mean you can resolve much smaller features. Chromatic aberration happens with sound exactly as it does with light (thus typically choosing an average wavelength of interest when making a light camera, whether using a refracting glass lens, a diffracting zone plate or pinhole), so you would only operate in a portion of the spectrum of sound, same as we only see the tiniest little sliver of the EM spectrum (no IR, UV, heat, X-rays, etc etc, even though they are otherwise identical). If your wavelength is on the order of 2 inches then any surface whose rough features are smaller than that will appear smooth / shiny / specular, as opposed to diffuse. But almost all of the calcs for light cameras should map directly to all other wave phenomena including sound.
If anybody has any interest in lending a hand or kicking around ideas, let me know. For now this is more a thought experiment while I get some other projects off my plate, but I'd love to work on it at some point and if anyone wants to help, it'll be more likely to be successful. I have basically all the calcs taken care of already for the pinhole/zone plate case as well as the phased array.
That's fair. Dave was talking about homebuilt condenser microphones
though.. Sonar and ultrasound work at higher frequencies.
Why not start with a single emitter and collector from a known distance and
see if you can get accurate readings then go on from there?
On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean.mcb...@gmail.com> wrote:
> Sound is direct enough to allow bats to navigate by it in the night. Sonar
> and ultrasound are types of acoustic imaging, and these days can make some
> very detailed pictures. So I have no doubt this can be done.
> The implications for 3d imaging are kind of exciting. The Xbox Kinect does
> it's depth sensing with infrared light, presuming that brighter pixels are
> closer pixels. Of course, put something that is very infrared-reflective in
> the scene and it breaks that assumption. With sound, it's slow enough that
> you could clock the amount of time it takes to bounce off of things,
> triangulate the bounces, and come up with a 3d picture.
> Let me know if you get around to working on this, would definitely like to
> help.
> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>> I'd like to hear Brendans take on this. From what I understand light
>> travels in a fairly direct line while sound doesn't.
>> Maybe an ultrasonic emitter and all the collectors on a concave surface?
>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <kyleyankan...@gmail.com> wrote:
>>> I'm really curious as to the images this will produce. From what I
>>> understand, sounds scatters much more than light. It influences the air of
>>> the room, mixing and creating some chaos in the airflow. Focusing.an image
>>> of that would be.... Difficult. Akin to taking a regular photograph, but in
>>> a foggy room. Except also the fog interacts with itself. I'd also be
>>> curious as to how the "focusing" effect would change. It normal
>>> photography, as the lens is moved from the photo sensitive material, it
>>> changes the distance of focus. Sometimes, since lights different colors are
>>> different wavelengths, you get different colors focusing.differently. its
>>> called.chromatic.aberation. Since sounds wavelengths are so much larger,
>>> does that mean we'll be effectively tuning out whole parts of the audio
>>> wavelengths?
>>> --
>>> To post to this group, send email to hive76-discussion@googlegroups.com
>>> To unsubscribe send email to
>>> hive76-discussion+unsubscribe@googlegroups.com
>>> For more awesome goto
>>> http://groups.google.com/group/hive76-discussion?hl=en
>> --
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>> To unsubscribe send email to
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> --
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I bet the homebrew condenser mics could be made to handle ultrasonic without much trouble, if that's what you wanted to do. Probably wouldn't even have to do anything different unless you wanted it to be optimal.
That's my plan to start with: set up a sound source somewhere (little piezo buzzer or something), put up a pinhole of the appropriate size and material, at the right distance from the mic. Move the mic around manually to different positions on a grid, and assemble a picture. I have no doubt whether or not it would work, it's just a matter of how well. Try holding up a helium balloon near your ear, the ambient room sound deadens dramatically, it's pretty eerie.
On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
> That's fair. Dave was talking about homebuilt condenser microphones > though.. Sonar and ultrasound work at higher frequencies.
> Why not start with a single emitter and collector from a known distance > and see if you can get accurate readings then go on from there? > On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com <javascript:>> > wrote:
>> Sound is direct enough to allow bats to navigate by it in the night. >> Sonar and ultrasound are types of acoustic imaging, and these days can make >> some very detailed pictures. So I have no doubt this can be done.
>> The implications for 3d imaging are kind of exciting. The Xbox Kinect >> does it's depth sensing with infrared light, presuming that brighter pixels >> are closer pixels. Of course, put something that is very >> infrared-reflective in the scene and it breaks that assumption. With sound, >> it's slow enough that you could clock the amount of time it takes to bounce >> off of things, triangulate the bounces, and come up with a 3d picture.
>> Let me know if you get around to working on this, would definitely like >> to help.
>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>> I'd like to hear Brendans take on this. From what I understand light >>> travels in a fairly direct line while sound doesn't.
>>> Maybe an ultrasonic emitter and all the collectors on a concave surface? >>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>> I'm really curious as to the images this will produce. From what I >>>> understand, sounds scatters much more than light. It influences the air of >>>> the room, mixing and creating some chaos in the airflow. Focusing.an image >>>> of that would be.... Difficult. Akin to taking a regular photograph, but in >>>> a foggy room. Except also the fog interacts with itself. I'd also be >>>> curious as to how the "focusing" effect would change. It normal >>>> photography, as the lens is moved from the photo sensitive material, it >>>> changes the distance of focus. Sometimes, since lights different colors are >>>> different wavelengths, you get different colors focusing.differently. its >>>> called.chromatic.aberation. Since sounds wavelengths are so much larger, >>>> does that mean we'll be effectively tuning out whole parts of the audio >>>> wavelengths?
>>>> -- >>>> To post to this group, send email to hive76-discussion@googlegroups.com >>>> To unsubscribe send email to >>>> hive76-discussion+unsubscribe@googlegroups.com >>>> For more awesome goto >>>> http://groups.google.com/group/hive76-discussion?hl=en
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I don't know anything about the electronics in this instance but would like
to help build the mechanical bits, certainly the pinhole mic. I have 1/2"
square by 4' foam rods left over from a quadratic diffuser build if you
want them.
On Oct 7, 2012 10:23 AM, "Dave" <dgsh...@gmail.com> wrote:
> I bet the homebrew condenser mics could be made to handle ultrasonic
> without much trouble, if that's what you wanted to do. Probably wouldn't
> even have to do anything different unless you wanted it to be optimal.
> That's my plan to start with: set up a sound source somewhere (little
> piezo buzzer or something), put up a pinhole of the appropriate size and
> material, at the right distance from the mic. Move the mic around manually
> to different positions on a grid, and assemble a picture. I have no doubt
> whether or not it would work, it's just a matter of how well. Try holding
> up a helium balloon near your ear, the ambient room sound deadens
> dramatically, it's pretty eerie.
> -Dave
> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
>> That's fair. Dave was talking about homebuilt condenser microphones
>> though.. Sonar and ultrasound work at higher frequencies.
>> Why not start with a single emitter and collector from a known distance
>> and see if you can get accurate readings then go on from there?
>> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
>>> Sound is direct enough to allow bats to navigate by it in the night.
>>> Sonar and ultrasound are types of acoustic imaging, and these days can make
>>> some very detailed pictures. So I have no doubt this can be done.
>>> The implications for 3d imaging are kind of exciting. The Xbox Kinect
>>> does it's depth sensing with infrared light, presuming that brighter pixels
>>> are closer pixels. Of course, put something that is very
>>> infrared-reflective in the scene and it breaks that assumption. With sound,
>>> it's slow enough that you could clock the amount of time it takes to bounce
>>> off of things, triangulate the bounces, and come up with a 3d picture.
>>> Let me know if you get around to working on this, would definitely like
>>> to help.
>>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>>> I'd like to hear Brendans take on this. From what I understand light
>>>> travels in a fairly direct line while sound doesn't.
>>>> Maybe an ultrasonic emitter and all the collectors on a concave
>>>> surface?
>>>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>>> I'm really curious as to the images this will produce. From what I
>>>>> understand, sounds scatters much more than light. It influences the air of
>>>>> the room, mixing and creating some chaos in the airflow. Focusing.an image
>>>>> of that would be.... Difficult. Akin to taking a regular photograph, but in
>>>>> a foggy room. Except also the fog interacts with itself. I'd also be
>>>>> curious as to how the "focusing" effect would change. It normal
>>>>> photography, as the lens is moved from the photo sensitive material, it
>>>>> changes the distance of focus. Sometimes, since lights different colors are
>>>>> different wavelengths, you get different colors focusing.differently. its
>>>>> called.chromatic.aberation. Since sounds wavelengths are so much larger,
>>>>> does that mean we'll be effectively tuning out whole parts of the audio
>>>>> wavelengths?
>>>>> --
>>>>> To post to this group, send email to hive76-discussion@**
>>>>> googlegroups.com
>>>>> To unsubscribe send email to hive76-discussion+unsubscribe@**
>>>>> googlegroups.com
>>>>> For more awesome goto http://groups.google.com/** >>>>> group/hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>>>> --
>>>> To post to this group, send email to hive76-discussion@**
>>>> googlegroups.com
>>>> To unsubscribe send email to hive76-discussion+unsubscribe@**
>>>> googlegroups.com
>>>> For more awesome goto http://groups.google.com/** >>>> group/hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>> --
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I think this is an awesome project, and I'm really excited to see how it works out, and of course available to help in any way I can. Dave, I think the trouble I'm having with this vs the bat/whale thing is that they measure distance to an object, using a relatively known frequency that they emit. In my mind, a camera is passive. It measure existing light levels, so ideally a sound-camera would do the same. It wouldn't so much as show the physical shape/properties of the room, but rather be a more .... abstract image. Almost a heat map of a 3 dimensional space, showing where sound is coming from.
The other one is just a depth-map of a room, which is neat as hell, but already kind of done in various ways.
On Sunday, October 7, 2012 10:36:38 AM UTC-4, J.Johnson wrote:
> I don't know anything about the electronics in this instance but would > like to help build the mechanical bits, certainly the pinhole mic. I have > 1/2" square by 4' foam rods left over from a quadratic diffuser build if > you want them. > On Oct 7, 2012 10:23 AM, "Dave" <dgs...@gmail.com <javascript:>> wrote:
>> I bet the homebrew condenser mics could be made to handle ultrasonic >> without much trouble, if that's what you wanted to do. Probably wouldn't >> even have to do anything different unless you wanted it to be optimal.
>> That's my plan to start with: set up a sound source somewhere (little >> piezo buzzer or something), put up a pinhole of the appropriate size and >> material, at the right distance from the mic. Move the mic around manually >> to different positions on a grid, and assemble a picture. I have no doubt >> whether or not it would work, it's just a matter of how well. Try holding >> up a helium balloon near your ear, the ambient room sound deadens >> dramatically, it's pretty eerie.
>> -Dave
>> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
>>> That's fair. Dave was talking about homebuilt condenser microphones >>> though.. Sonar and ultrasound work at higher frequencies.
>>> Why not start with a single emitter and collector from a known distance >>> and see if you can get accurate readings then go on from there? >>> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
>>>> Sound is direct enough to allow bats to navigate by it in the night. >>>> Sonar and ultrasound are types of acoustic imaging, and these days can make >>>> some very detailed pictures. So I have no doubt this can be done.
>>>> The implications for 3d imaging are kind of exciting. The Xbox Kinect >>>> does it's depth sensing with infrared light, presuming that brighter pixels >>>> are closer pixels. Of course, put something that is very >>>> infrared-reflective in the scene and it breaks that assumption. With sound, >>>> it's slow enough that you could clock the amount of time it takes to bounce >>>> off of things, triangulate the bounces, and come up with a 3d picture.
>>>> Let me know if you get around to working on this, would definitely like >>>> to help.
>>>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>>>> I'd like to hear Brendans take on this. From what I understand light >>>>> travels in a fairly direct line while sound doesn't.
>>>>> Maybe an ultrasonic emitter and all the collectors on a concave >>>>> surface? >>>>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>>>> I'm really curious as to the images this will produce. From what I >>>>>> understand, sounds scatters much more than light. It influences the air of >>>>>> the room, mixing and creating some chaos in the airflow. Focusing.an image >>>>>> of that would be.... Difficult. Akin to taking a regular photograph, but in >>>>>> a foggy room. Except also the fog interacts with itself. I'd also be >>>>>> curious as to how the "focusing" effect would change. It normal >>>>>> photography, as the lens is moved from the photo sensitive material, it >>>>>> changes the distance of focus. Sometimes, since lights different colors are >>>>>> different wavelengths, you get different colors focusing.differently. its >>>>>> called.chromatic.aberation. Since sounds wavelengths are so much larger, >>>>>> does that mean we'll be effectively tuning out whole parts of the audio >>>>>> wavelengths?
>>>>>> -- >>>>>> To post to this group, send email to hive76-discussion@** >>>>>> googlegroups.com >>>>>> To unsubscribe send email to hive76-discussion+unsubscribe@** >>>>>> googlegroups.com >>>>>> For more awesome goto http://groups.google.com/** >>>>>> group/hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>>>>> -- >>>>> To post to this group, send email to hive76-discussion@** >>>>> googlegroups.com >>>>> To unsubscribe send email to hive76-discussion+unsubscribe@** >>>>> googlegroups.com >>>>> For more awesome goto http://groups.google.com/** >>>>> group/hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>>> -- >> To post to this group, send email to hive76-d...@googlegroups.com<javascript:> >> To unsubscribe send email to hive76-discuss...@googlegroups.com<javascript:> >> For more awesome goto >> http://groups.google.com/group/hive76-discussion?hl=en
Kyle, yes, this is a passive sensor. As with light cameras you can always provide your own illumination if there's not enough signal out there already for you to pick up. This is not about depth, but measuring the energy coming from different regions. Seeing the shape and structure of the environment. Abstract. I'm not expecting this to replace light cameras...
I haven't seen every post in this discussion, so my apologies if this has
already been discussed, but this is currently being done to image babies in
the womb - http://en.wikipedia.org/wiki/3D_ultrasound. Might be
some literature that can be leveraged in choosing frequencies / imaging the
result.
On Sun, Oct 7, 2012 at 1:37 PM, Kyle Yankanich <kyleyankan...@gmail.com>wrote:
> I think this is an awesome project, and I'm really excited to see how it
> works out, and of course available to help in any way I can. Dave, I think
> the trouble I'm having with this vs the bat/whale thing is that they
> measure distance to an object, using a relatively known frequency that they
> emit. In my mind, a camera is passive. It measure existing light levels, so
> ideally a sound-camera would do the same. It wouldn't so much as show the
> physical shape/properties of the room, but rather be a more .... abstract
> image. Almost a heat map of a 3 dimensional space, showing where sound is
> coming from.
> The other one is just a depth-map of a room, which is neat as hell, but
> already kind of done in various ways.
> On Sunday, October 7, 2012 10:36:38 AM UTC-4, J.Johnson wrote:
>> I don't know anything about the electronics in this instance but would
>> like to help build the mechanical bits, certainly the pinhole mic. I have
>> 1/2" square by 4' foam rods left over from a quadratic diffuser build if
>> you want them.
>> On Oct 7, 2012 10:23 AM, "Dave" <dgs...@gmail.com> wrote:
>>> I bet the homebrew condenser mics could be made to handle ultrasonic
>>> without much trouble, if that's what you wanted to do. Probably wouldn't
>>> even have to do anything different unless you wanted it to be optimal.
>>> That's my plan to start with: set up a sound source somewhere (little
>>> piezo buzzer or something), put up a pinhole of the appropriate size and
>>> material, at the right distance from the mic. Move the mic around manually
>>> to different positions on a grid, and assemble a picture. I have no doubt
>>> whether or not it would work, it's just a matter of how well. Try holding
>>> up a helium balloon near your ear, the ambient room sound deadens
>>> dramatically, it's pretty eerie.
>>> -Dave
>>> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
>>>> That's fair. Dave was talking about homebuilt condenser microphones
>>>> though.. Sonar and ultrasound work at higher frequencies.
>>>> Why not start with a single emitter and collector from a known distance
>>>> and see if you can get accurate readings then go on from there?
>>>> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
>>>>> Sound is direct enough to allow bats to navigate by it in the night.
>>>>> Sonar and ultrasound are types of acoustic imaging, and these days can make
>>>>> some very detailed pictures. So I have no doubt this can be done.
>>>>> The implications for 3d imaging are kind of exciting. The Xbox Kinect
>>>>> does it's depth sensing with infrared light, presuming that brighter pixels
>>>>> are closer pixels. Of course, put something that is very
>>>>> infrared-reflective in the scene and it breaks that assumption. With sound,
>>>>> it's slow enough that you could clock the amount of time it takes to bounce
>>>>> off of things, triangulate the bounces, and come up with a 3d picture.
>>>>> Let me know if you get around to working on this, would definitely
>>>>> like to help.
>>>>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>>>>> I'd like to hear Brendans take on this. From what I understand light
>>>>>> travels in a fairly direct line while sound doesn't.
>>>>>> Maybe an ultrasonic emitter and all the collectors on a concave
>>>>>> surface?
>>>>>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>>>>> I'm really curious as to the images this will produce. From what I
>>>>>>> understand, sounds scatters much more than light. It influences the air of
>>>>>>> the room, mixing and creating some chaos in the airflow. Focusing.an image
>>>>>>> of that would be.... Difficult. Akin to taking a regular photograph, but in
>>>>>>> a foggy room. Except also the fog interacts with itself. I'd also be
>>>>>>> curious as to how the "focusing" effect would change. It normal
>>>>>>> photography, as the lens is moved from the photo sensitive material, it
>>>>>>> changes the distance of focus. Sometimes, since lights different colors are
>>>>>>> different wavelengths, you get different colors focusing.differently. its
>>>>>>> called.chromatic.aberation. Since sounds wavelengths are so much larger,
>>>>>>> does that mean we'll be effectively tuning out whole parts of the audio
>>>>>>> wavelengths?
>>>>>>> --
>>>>>>> To post to this group, send email to hive76-discussion@**
>>>>>>> googlegroups**.com
>>>>>>> To unsubscribe send email to hive76-discussion+unsubscribe@****
>>>>>>> googlegroups.com
>>>>>>> For more awesome goto http://groups.google.com/**group** >>>>>>> /hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>> --
> To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to
> hive76-discussion+unsubscribe@googlegroups.com
> For more awesome goto
> http://groups.google.com/group/hive76-discussion?hl=en
Err this seems a bit different from regular ultrasound -- although pez's idea for a coherent phased array is getting there. I have never heard of an ultrasound machine that used an actual aperture, for one thing. Or audible frequencies. Or one that is the size of a large room. I think this project is hot
On Oct 7, 2012, at 2:42 PM, Dan Shookowsky <dshookow...@gmail.com> wrote:
> I haven't seen every post in this discussion, so my apologies if this has already been discussed, but this is currently being done to image babies in the womb - http://en.wikipedia.org/wiki/3D_ultrasound. Might be some literature that can be leveraged in choosing frequencies / imaging the result.
> On Sun, Oct 7, 2012 at 1:37 PM, Kyle Yankanich <kyleyankan...@gmail.com> wrote:
> I think this is an awesome project, and I'm really excited to see how it works out, and of course available to help in any way I can. Dave, I think the trouble I'm having with this vs the bat/whale thing is that they measure distance to an object, using a relatively known frequency that they emit. In my mind, a camera is passive. It measure existing light levels, so ideally a sound-camera would do the same. It wouldn't so much as show the physical shape/properties of the room, but rather be a more .... abstract image. Almost a heat map of a 3 dimensional space, showing where sound is coming from.
> The other one is just a depth-map of a room, which is neat as hell, but already kind of done in various ways.
> On Sunday, October 7, 2012 10:36:38 AM UTC-4, J.Johnson wrote:
> I don't know anything about the electronics in this instance but would like to help build the mechanical bits, certainly the pinhole mic. I have 1/2" square by 4' foam rods left over from a quadratic diffuser build if you want them.
> On Oct 7, 2012 10:23 AM, "Dave" <dgs...@gmail.com> wrote:
> I bet the homebrew condenser mics could be made to handle ultrasonic without much trouble, if that's what you wanted to do. Probably wouldn't even have to do anything different unless you wanted it to be optimal.
> That's my plan to start with: set up a sound source somewhere (little piezo buzzer or something), put up a pinhole of the appropriate size and material, at the right distance from the mic. Move the mic around manually to different positions on a grid, and assemble a picture. I have no doubt whether or not it would work, it's just a matter of how well. Try holding up a helium balloon near your ear, the ambient room sound deadens dramatically, it's pretty eerie.
> -Dave
> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
> That's fair. Dave was talking about homebuilt condenser microphones though.. Sonar and ultrasound work at higher frequencies.
> Why not start with a single emitter and collector from a known distance and see if you can get accurate readings then go on from there?
> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
> Sound is direct enough to allow bats to navigate by it in the night. Sonar and ultrasound are types of acoustic imaging, and these days can make some very detailed pictures. So I have no doubt this can be done.
> The implications for 3d imaging are kind of exciting. The Xbox Kinect does it's depth sensing with infrared light, presuming that brighter pixels are closer pixels. Of course, put something that is very infrared-reflective in the scene and it breaks that assumption. With sound, it's slow enough that you could clock the amount of time it takes to bounce off of things, triangulate the bounces, and come up with a 3d picture.
> Let me know if you get around to working on this, would definitely like to help.
> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
> I'd like to hear Brendans take on this. From what I understand light travels in a fairly direct line while sound doesn't.
> Maybe an ultrasonic emitter and all the collectors on a concave surface?
> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
> I'm really curious as to the images this will produce. From what I understand, sounds scatters much more than light. It influences the air of the room, mixing and creating some chaos in the airflow. Focusing.an image of that would be.... Difficult. Akin to taking a regular photograph, but in a foggy room. Except also the fog interacts with itself. I'd also be curious as to how the "focusing" effect would change. It normal photography, as the lens is moved from the photo sensitive material, it changes the distance of focus. Sometimes, since lights different colors are different wavelengths, you get different colors focusing.differently. its called.chromatic.aberation. Since sounds wavelengths are so much larger, does that mean we'll be effectively tuning out whole parts of the audio wavelengths?
> --
> To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to hive76-discussion+unsubscribe@googlegroups.com
> For more awesome goto http://groups.google.com/group/hive76-discussion?hl=en > -- > To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to hive76-discussion+unsubscribe@googlegroups.com
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> For more awesome goto http://groups.google.com/group/hive76-discussion?hl=en
> -- > To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to hive76-discussion+unsubscribe@googlegroups.com
> For more awesome goto http://groups.google.com/group/hive76-discussion?hl=en
On Sun, Oct 7, 2012 at 2:57 PM, Jack Zylkin <jzyl...@gmail.com> wrote:
> Err this seems a bit different from regular ultrasound -- although pez's
> idea for a coherent phased array is getting there. I have never heard of
> an ultrasound machine that used an actual aperture, for one thing. Or
> audible frequencies. Or one that is the size of a large room. I think
> this project is hot
> On Oct 7, 2012, at 2:42 PM, Dan Shookowsky <dshookow...@gmail.com> wrote:
> I haven't seen every post in this discussion, so my apologies if this has
> already been discussed, but this is currently being done to image babies in
> the womb - http://en.wikipedia.org/wiki/3D_ultrasound. Might be
> some literature that can be leveraged in choosing frequencies / imaging the
> result.
> On Sun, Oct 7, 2012 at 1:37 PM, Kyle Yankanich <kyleyankan...@gmail.com>wrote:
>> I think this is an awesome project, and I'm really excited to see how it
>> works out, and of course available to help in any way I can. Dave, I think
>> the trouble I'm having with this vs the bat/whale thing is that they
>> measure distance to an object, using a relatively known frequency that they
>> emit. In my mind, a camera is passive. It measure existing light levels, so
>> ideally a sound-camera would do the same. It wouldn't so much as show the
>> physical shape/properties of the room, but rather be a more .... abstract
>> image. Almost a heat map of a 3 dimensional space, showing where sound is
>> coming from.
>> The other one is just a depth-map of a room, which is neat as hell, but
>> already kind of done in various ways.
>> On Sunday, October 7, 2012 10:36:38 AM UTC-4, J.Johnson wrote:
>>> I don't know anything about the electronics in this instance but would
>>> like to help build the mechanical bits, certainly the pinhole mic. I have
>>> 1/2" square by 4' foam rods left over from a quadratic diffuser build if
>>> you want them.
>>> On Oct 7, 2012 10:23 AM, "Dave" <dgs...@gmail.com> wrote:
>>>> I bet the homebrew condenser mics could be made to handle ultrasonic
>>>> without much trouble, if that's what you wanted to do. Probably wouldn't
>>>> even have to do anything different unless you wanted it to be optimal.
>>>> That's my plan to start with: set up a sound source somewhere (little
>>>> piezo buzzer or something), put up a pinhole of the appropriate size and
>>>> material, at the right distance from the mic. Move the mic around manually
>>>> to different positions on a grid, and assemble a picture. I have no doubt
>>>> whether or not it would work, it's just a matter of how well. Try holding
>>>> up a helium balloon near your ear, the ambient room sound deadens
>>>> dramatically, it's pretty eerie.
>>>> -Dave
>>>> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
>>>>> That's fair. Dave was talking about homebuilt condenser microphones
>>>>> though.. Sonar and ultrasound work at higher frequencies.
>>>>> Why not start with a single emitter and collector from a known
>>>>> distance and see if you can get accurate readings then go on from there?
>>>>> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
>>>>>> Sound is direct enough to allow bats to navigate by it in the night.
>>>>>> Sonar and ultrasound are types of acoustic imaging, and these days can make
>>>>>> some very detailed pictures. So I have no doubt this can be done.
>>>>>> The implications for 3d imaging are kind of exciting. The Xbox Kinect
>>>>>> does it's depth sensing with infrared light, presuming that brighter pixels
>>>>>> are closer pixels. Of course, put something that is very
>>>>>> infrared-reflective in the scene and it breaks that assumption. With sound,
>>>>>> it's slow enough that you could clock the amount of time it takes to bounce
>>>>>> off of things, triangulate the bounces, and come up with a 3d picture.
>>>>>> Let me know if you get around to working on this, would definitely
>>>>>> like to help.
>>>>>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>>>>>> I'd like to hear Brendans take on this. From what I understand light
>>>>>>> travels in a fairly direct line while sound doesn't.
>>>>>>> Maybe an ultrasonic emitter and all the collectors on a concave
>>>>>>> surface?
>>>>>>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>>>>>> I'm really curious as to the images this will produce. From what I
>>>>>>>> understand, sounds scatters much more than light. It influences the air of
>>>>>>>> the room, mixing and creating some chaos in the airflow. Focusing.an image
>>>>>>>> of that would be.... Difficult. Akin to taking a regular photograph, but in
>>>>>>>> a foggy room. Except also the fog interacts with itself. I'd also be
>>>>>>>> curious as to how the "focusing" effect would change. It normal
>>>>>>>> photography, as the lens is moved from the photo sensitive material, it
>>>>>>>> changes the distance of focus. Sometimes, since lights different colors are
>>>>>>>> different wavelengths, you get different colors focusing.differently. its
>>>>>>>> called.chromatic.aberation. Since sounds wavelengths are so much larger,
>>>>>>>> does that mean we'll be effectively tuning out whole parts of the audio
>>>>>>>> wavelengths?
>>>>>>>> --
>>>>>>>> To post to this group, send email to hive76-discussion@**
>>>>>>>> googlegroups**.com
>>>>>>>> To unsubscribe send email to hive76-discussion+unsubscribe@****
>>>>>>>> googlegroups.com
>>>>>>>> For more awesome goto http://groups.google.com/**group** >>>>>>>> /hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>>>>>>> --
>>>>>>> To post to this group, send email to hive76-discussion@**
>>>>>>> googlegroups**.com
>>>>>>> To unsubscribe send email to hive76-discussion+unsubscribe@****
>>>>>>> googlegroups.com
>>>>>>> For more awesome goto http://groups.google.com/**group** >>>>>>> /hive76-discussion?hl=en<http://groups.google.com/group/hive76-discussion?hl=en>
>>> --
>> To post to this group, send email to hive76-discussion@googlegroups.com
>> To unsubscribe send email to
>> hive76-discussion+unsubscribe@googlegroups.com
>> For more awesome goto
>> http://groups.google.com/group/hive76-discussion?hl=en
> --
> To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to
> hive76-discussion+unsubscribe@googlegroups.com
> For more awesome goto
> http://groups.google.com/group/hive76-discussion?hl=en
> --
> To post to this group, send email to hive76-discussion@googlegroups.com
> To unsubscribe send email to
> hive76-discussion+unsubscribe@googlegroups.com
> For more awesome goto
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This whole thing sounds pretty cool. It would be cool to see a real-time image of, say, someone talking in a room, turning about... It would let you see how the sound reflects about the room.
On Sunday, October 7, 2012 2:58:59 PM UTC-4, Dan Shookowsky wrote:
> See, that's why I should've RTFT. I missed the part about audible > frequencies and a room-sized device.
> On Sun, Oct 7, 2012 at 2:57 PM, Jack Zylkin <jzy...@gmail.com<javascript:> > > wrote:
>> Err this seems a bit different from regular ultrasound -- although pez's >> idea for a coherent phased array is getting there. I have never heard of >> an ultrasound machine that used an actual aperture, for one thing. Or >> audible frequencies. Or one that is the size of a large room. I think >> this project is hot
>> On Oct 7, 2012, at 2:42 PM, Dan Shookowsky <dshoo...@gmail.com<javascript:>> >> wrote:
>> I haven't seen every post in this discussion, so my apologies if this has >> already been discussed, but this is currently being done to image babies in >> the womb - http://en.wikipedia.org/wiki/3D_ultrasound. Might be >> some literature that can be leveraged in choosing frequencies / imaging the >> result.
>> On Sun, Oct 7, 2012 at 1:37 PM, Kyle Yankanich <kyleya...@gmail.com<javascript:> >> > wrote:
>>> I think this is an awesome project, and I'm really excited to see how it >>> works out, and of course available to help in any way I can. Dave, I think >>> the trouble I'm having with this vs the bat/whale thing is that they >>> measure distance to an object, using a relatively known frequency that they >>> emit. In my mind, a camera is passive. It measure existing light levels, so >>> ideally a sound-camera would do the same. It wouldn't so much as show the >>> physical shape/properties of the room, but rather be a more .... abstract >>> image. Almost a heat map of a 3 dimensional space, showing where sound is >>> coming from.
>>> The other one is just a depth-map of a room, which is neat as hell, but >>> already kind of done in various ways.
>>> On Sunday, October 7, 2012 10:36:38 AM UTC-4, J.Johnson wrote:
>>>> I don't know anything about the electronics in this instance but would >>>> like to help build the mechanical bits, certainly the pinhole mic. I have >>>> 1/2" square by 4' foam rods left over from a quadratic diffuser build if >>>> you want them. >>>> On Oct 7, 2012 10:23 AM, "Dave" <dgs...@gmail.com> wrote:
>>>>> I bet the homebrew condenser mics could be made to handle ultrasonic >>>>> without much trouble, if that's what you wanted to do. Probably wouldn't >>>>> even have to do anything different unless you wanted it to be optimal.
>>>>> That's my plan to start with: set up a sound source somewhere (little >>>>> piezo buzzer or something), put up a pinhole of the appropriate size and >>>>> material, at the right distance from the mic. Move the mic around manually >>>>> to different positions on a grid, and assemble a picture. I have no doubt >>>>> whether or not it would work, it's just a matter of how well. Try holding >>>>> up a helium balloon near your ear, the ambient room sound deadens >>>>> dramatically, it's pretty eerie.
>>>>> -Dave
>>>>> On Sunday, October 7, 2012 9:39:47 AM UTC-4, J.Johnson wrote:
>>>>>> That's fair. Dave was talking about homebuilt condenser microphones >>>>>> though.. Sonar and ultrasound work at higher frequencies.
>>>>>> Why not start with a single emitter and collector from a known >>>>>> distance and see if you can get accurate readings then go on from there? >>>>>> On Oct 7, 2012 9:27 AM, "Sean McBeth" <sean....@gmail.com> wrote:
>>>>>>> Sound is direct enough to allow bats to navigate by it in the night. >>>>>>> Sonar and ultrasound are types of acoustic imaging, and these days can make >>>>>>> some very detailed pictures. So I have no doubt this can be done.
>>>>>>> The implications for 3d imaging are kind of exciting. The Xbox >>>>>>> Kinect does it's depth sensing with infrared light, presuming that brighter >>>>>>> pixels are closer pixels. Of course, put something that is very >>>>>>> infrared-reflective in the scene and it breaks that assumption. With sound, >>>>>>> it's slow enough that you could clock the amount of time it takes to bounce >>>>>>> off of things, triangulate the bounces, and come up with a 3d picture.
>>>>>>> Let me know if you get around to working on this, would definitely >>>>>>> like to help.
>>>>>>> On Sunday, October 7, 2012, Joshua D. Johnson wrote:
>>>>>>>> I'd like to hear Brendans take on this. From what I understand >>>>>>>> light travels in a fairly direct line while sound doesn't.
>>>>>>>> Maybe an ultrasonic emitter and all the collectors on a concave >>>>>>>> surface? >>>>>>>> On Oct 7, 2012 8:42 AM, "Kyle Yankanich" <> wrote:
>>>>>>>>> I'm really curious as to the images this will produce. From what I >>>>>>>>> understand, sounds scatters much more than light. It influences the air of >>>>>>>>> the room, mixing and creating some chaos in the airflow. Focusing.an image >>>>>>>>> of that would be.... Difficult. Akin to taking a regular photograph, but in >>>>>>>>> a foggy room. Except also the fog interacts with itself. I'd also be >>>>>>>>> curious as to how the "focusing" effect would change. It normal >>>>>>>>> photography, as the lens is moved from the photo sensitive material, it >>>>>>>>> changes the distance of focus. Sometimes, since lights different colors are >>>>>>>>> different wavelengths, you get different colors focusing.differently. its >>>>>>>>> called.chromatic.aberation. Since sounds wavelengths are so much larger, >>>>>>>>> does that mean we'll be effectively tuning out whole parts of the audio >>>>>>>>> wavelengths?
>>>>>>>>> -- >>>>>>>>> To post to this group, send email to >>>>>>>>> hive76-discussion@googlegroups.com >>>>>>>>> To unsubscribe send email to >>>>>>>>> hive76-discussion+unsubscribe@googlegroups.com >>>>>>>>> For more awesome goto >>>>>>>>> http://groups.google.com/group/hive76-discussion?hl=en
>>>>>>>> -- >>>>>>>> To post to this group, send email to >>>>>>>> hive76-discussion@googlegroups.com >>>>>>>> To unsubscribe send email to >>>>>>>> hive76-discussion+unsubscribe@googlegroups.com >>>>>>>> For more awesome goto >>>>>>>> http://groups.google.com/group/hive76-discussion?hl=en
>>>>>>> -- >>>>>>> To post to this group, send email to hive76-d...@googlegroups.com >>>>>>> To unsubscribe send email to hive76-discuss...@googlegroups.com >>>>>>> For more awesome goto >>>>>>> http://groups.google.com/group/hive76-discussion?hl=en
>>>>>> -- >>>>> To post to this group, send email to hive76-d...@googlegroups.com >>>>> To unsubscribe send email to hive76-discuss...@googlegroups.com >>>>> For more awesome goto >>>>> http://groups.google.com/group/hive76-discussion?hl=en
>>>> -- >>> To post to this group, send email to hive76-d...@googlegroups.com<javascript:> >>> To unsubscribe send email to hive76-discuss...@googlegroups.com<javascript:> >>> For more awesome goto >>> http://groups.google.com/group/hive76-discussion?hl=en
>> -- >> To post to this group, send email to hive76-d...@googlegroups.com<javascript:> >> To unsubscribe send email to hive76-discuss...@googlegroups.com<javascript:> >> For more awesome goto >> http://groups.google.com/group/hive76-discussion?hl=en
>> -- >> To post to this group, send email to hive76-d...@googlegroups.com<javascript:> >> To unsubscribe send email to hive76-discuss...@googlegroups.com<javascript:> >> For more awesome goto >> http://groups.google.com/group/hive76-discussion?hl=en
One disadvantage we may have is related to the type of sensor. In a digital light camera, each pixel is basically a small solar cell, and whenever a photon of sufficient energy is absored, it knocks an electron loose and traps it in an electron well. In a real light camera the integration time is how long you allow the electron wells to collect more electrons before you measure the contents. If that time is too low then you don't get much signal, and if it's too high then the well fills up and saturates, but the great thing is it allows you to basically count photons, with extremely low noise. In my proposed approach we would be sampling the mic channel many times per period of the acoustic frequency of interest and doing a little signal processing, and each sample has a certain small ADC noise. That noise floor basically sets the threshold below which we just can't reliably pick up a signal, unlike the ideal light imager that can potentially just keep capturing more photons and accumulating a stronger signal before measuring it if you just leave the 'shutter' open long enough.
This is not a difference between light and sound, just a difference in the electronics we have available to us. The idea works, this just means the tech is not as advanced as today's imaging chips. We'd be in exactly the same boat if we were building our own light camera by hand (I, for one, would have no idea how to build an electron well from scratch). If anybody has any ideas of how to approximate something like this with sound I'd be curious to hear though. As it is, this is just the acoustic equivalent of having a camera with poor low-light sensitivity, so we can only shoot brightly lit scenes.
On Sun, Oct 7, 2012 at 10:29 PM, Dave <dgsh...@gmail.com> wrote:
> One disadvantage we may have is related to the type of sensor. In a digital light camera, each pixel is basically a small solar cell, and whenever a photon of sufficient energy is absored, it knocks an electron loose and traps it in an electron well. In a real light camera the integration time is how long you allow the electron wells to collect more electrons before you measure the contents. If that time is too low then you don't get much signal, and if it's too high then the well fills up and saturates, but the great thing is it allows you to basically count photons, with extremely low noise. In my proposed approach we would be sampling the mic channel many times per period of the acoustic frequency of interest and doing a little signal processing, and each sample has a certain small ADC noise. That noise floor basically sets the threshold below which we just can't reliably pick up a signal, unlike the ideal light imager that can potentially just keep capturing more photons and accumulating a stronger signal before measuring it if you just leave the 'shutter' open long enough.
> This is not a difference between light and sound, just a difference in the electronics we have available to us. The idea works, this just means the tech is not as advanced as today's imaging chips. We'd be in exactly the same boat if we were building our own light camera by hand (I, for one, would have no idea how to build an electron well from scratch). If anybody has any ideas of how to approximate something like this with sound I'd be curious to hear though. As it is, this is just the acoustic equivalent of having a camera with poor low-light sensitivity, so we can only shoot brightly lit scenes.
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Yeah there are some cool commercial products out there (all of them beamforming-oriented). But there's virtually nothing that's been done by hobbyists in this field. My cheesy transmitting acoustic phased array I brought in a few months ago was probably the only amateur phased array I've actually come across anywhere, which is kind of sad. I've been learning about FPGAs largely so I can do a better one some day. But there's just something attractive to me about the pinhole sound camera for some reason.
your pinhole will be way better than a phased array. Acoustic phased array
is more analogous to a radar than a camera. I mean, you don't see many
cameras out there without lenses or apertures.
On Sun, Oct 7, 2012 at 10:56 PM, Dave <dgsh...@gmail.com> wrote:
> Yeah there are some cool commercial products out there (all of them
> beamforming-oriented). But there's virtually nothing that's been done by
> hobbyists in this field. My cheesy transmitting acoustic phased array I
> brought in a few months ago was probably the only amateur phased array I've
> actually come across anywhere, which is kind of sad. I've been learning
> about FPGAs largely so I can do a better one some day. But there's just
> something attractive to me about the pinhole sound camera for some reason.
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On Mon, Oct 8, 2012 at 12:30 AM, Jack Zylkin <jzyl...@gmail.com> wrote:
> your pinhole will be way better than a phased array. Acoustic phased array
> is more analogous to a radar than a camera. I mean, you don't see many
> cameras out there without lenses or apertures.
> On Sun, Oct 7, 2012 at 10:56 PM, Dave <dgsh...@gmail.com> wrote:
>> Yeah there are some cool commercial products out there (all of them
>> beamforming-oriented). But there's virtually nothing that's been done by
>> hobbyists in this field. My cheesy transmitting acoustic phased array I
>> brought in a few months ago was probably the only amateur phased array I've
>> actually come across anywhere, which is kind of sad. I've been learning
>> about FPGAs largely so I can do a better one some day. But there's just
>> something attractive to me about the pinhole sound camera for some reason.
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>> hive76-discussion+unsubscribe@googlegroups.com
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> Jack Zylkin
> usbtypewriter.com
> Philadelphia, PA
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:) My calcs are actually all done for zone plates, and a pinhole is just the first zone of a zone plate, so it's smaller and easier to make. Zone plates add more gain and can improve the resolution some but are larger and a bit harder to make. One nice thing about a pinhole is that if you make it as an iris mechanism you can use it to change your focus and field of view (zoom) by adjusting its size and moving the imaging plane back and forth. Harder to do with a zone plate.
> On Mon, Oct 8, 2012 at 12:30 AM, Jack Zylkin <jzy...@gmail.com<javascript:>> > wrote: > > your pinhole will be way better than a phased array. Acoustic phased > array > > is more analogous to a radar than a camera. I mean, you don't see many > > cameras out there without lenses or apertures.
> > On Sun, Oct 7, 2012 at 10:56 PM, Dave <dgs...@gmail.com <javascript:>> > wrote:
> >> Yeah there are some cool commercial products out there (all of them > >> beamforming-oriented). But there's virtually nothing that's been done > by > >> hobbyists in this field. My cheesy transmitting acoustic phased array I > >> brought in a few months ago was probably the only amateur phased array > I've > >> actually come across anywhere, which is kind of sad. I've been learning > >> about FPGAs largely so I can do a better one some day. But there's just > >> something attractive to me about the pinhole sound camera for some > reason.
> >> -- > >> To post to this group, send email to hive76-d...@googlegroups.com<javascript:> > >> To unsubscribe send email to > >> hive76-discuss...@googlegroups.com <javascript:> > >> For more awesome goto > >> http://groups.google.com/group/hive76-discussion?hl=en
> > -- > > Jack Zylkin > > usbtypewriter.com > > Philadelphia, PA
> > -- > > To post to this group, send email to hive76-d...@googlegroups.com<javascript:> > > To unsubscribe send email to hive76-discuss...@googlegroups.com<javascript:> > > For more awesome goto > http://groups.google.com/group/hive76-discussion?hl=en
Yeah, those calculators are a good start. Once you start making unusual assumptions (nonstandard optical formats, huge wavelengths, etc) or needing more information (focus distance, feature resolution, field of view, etc) it's easier to just roll your own. I think for audio, starting out with a pinhole is probably better though -- easier, and more likely to work will. The material will likely have to be fairly thick, which I'm guessing would introduce more artifacts with a zone plate than a pinhole.
>> On Mon, Oct 8, 2012 at 12:30 AM, Jack Zylkin <jzy...@gmail.com> wrote: >> > your pinhole will be way better than a phased array. Acoustic phased >> array >> > is more analogous to a radar than a camera. I mean, you don't see many >> > cameras out there without lenses or apertures.
>> > On Sun, Oct 7, 2012 at 10:56 PM, Dave <dgs...@gmail.com> wrote:
>> >> Yeah there are some cool commercial products out there (all of them >> >> beamforming-oriented). But there's virtually nothing that's been done >> by >> >> hobbyists in this field. My cheesy transmitting acoustic phased array >> I >> >> brought in a few months ago was probably the only amateur phased array >> I've >> >> actually come across anywhere, which is kind of sad. I've been >> learning >> >> about FPGAs largely so I can do a better one some day. But there's >> just >> >> something attractive to me about the pinhole sound camera for some >> reason.
>> >> -- >> >> To post to this group, send email to hive76-d...@googlegroups.com >> >> To unsubscribe send email to >> >> hive76-discuss...@googlegroups.com >> >> For more awesome goto >> >> http://groups.google.com/group/hive76-discussion?hl=en
>> > -- >> > Jack Zylkin >> > usbtypewriter.com >> > Philadelphia, PA
>> > -- >> > To post to this group, send email to hive76-d...@googlegroups.com >> > To unsubscribe send email to hive76-discuss...@googlegroups.com >> > For more awesome goto >> http://groups.google.com/group/hive76-discussion?hl=en
