[HN Gopher] Smartphone Cameras Go Hyperspectral
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Smartphone Cameras Go Hyperspectral
Author : voxadam
Score : 86 points
Date : 2025-09-24 14:20 UTC (8 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| fkyoureadthedoc wrote:
| > The new patent-pending technique
|
| > "Every photo carries hidden spectral information waiting to be
| uncovered. By extracting it, we can turn everyday photography
| into science."
|
| And with our patent, extract rent from anyone who wants to do it!
| moritonal wrote:
| That's a bit of a bad faith take. You were welcome to go spend
| the years(?) this chaps dedicated to putting together the
| research required to build this. If it works, let him enjoy the
| fruits of labour.
| SequoiaHope wrote:
| Patents do more than let you enjoy the fruits of your labor -
| the market already allows for that. Patents use the force of
| law to bar anyone else who might have discovered the same
| thing from building upon it.
| spookie wrote:
| Imagine you are just a dude, you did all this work, and go
| to "market".
|
| You are just a dude, therefore business grows slowly.
|
| You gather enough attention that some corporation with a
| lot of bling just goes and copies your thing.
|
| Your business fails.
| fkyoureadthedoc wrote:
| On the other hand those same corporations can generate,
| file, and litigate more patents than just a dude could
| ever hope to.
|
| It's 2007. Just-a-dude has a great idea, he notices
| customers to his website often buy just one item, so
| he'll let them do that with one simple click. What's
| this, he's just received a cease and desist? Sorry bro,
| Amazon patented that 10 years ago.
| SequoiaHope wrote:
| Once can just as trivially construct an argument
| demonstrating the issue with patents but the problem with
| this style of argument is that patents are not a simple
| thing. They have global far reaching effects. The
| government distributing a monopoly on information is a
| serious interference with the market, and due to patent
| harmonization efforts across the world, one person filing
| a patent in New Jersey affects even people in Kenya and
| Turkey and Thailand. The arguments for patents are often,
| as I see it, based on a deeply flawed understanding of
| the motivations of innovators and the affects of open
| information on innovation. For example most arguments in
| favor of patents cannot explain how open source works,
| and so are clearly incomplete or outright wrong.
| BolexNOLA wrote:
| I mean we're basically getting the same result. Tons of
| businesses, not to mention patent trolls, constantly
| harass individuals and small businesses trying to get
| their foot in the door or just run a small, sustainable
| business. Hell forget my business failing, it's possible
| I'll never even get to try my idea out!
| serf wrote:
| you have it entirely backwards; patents dont protect
| just-a-dude, they protect the corporation.
|
| how?
|
| just-a-dude doesn't have a team of patent attorneys
| sitting in his back office waiting for work.
| dtj1123 wrote:
| Sure, if he'd come up with this primarly using his own
| resources and time, but he discovered this whilst being paid
| to conduct research at a public university, a form of
| institution which is explicitly intended to disseminate
| knowledge. Society should enjoy the fruits of its investment.
| slwvx wrote:
| I was hoping that someone came out with a camera that not only
| had not only sensors for visible light, but for infrared and UV.
| It's just another color to add to the sensors; I think we have
| enough megapixels, seems like going for other bands is
| reasonable.
| Scene_Cast2 wrote:
| I have a OnePlus 8 Pro with an IR camera. It's pretty nifty -
| nature photography looks cool, seeing through stovetops is neat
| (and seeing when they heat up), and VR things are also often
| playing around with IR (plastic transparent to IR, IR LEDs,
| etc).
|
| I ended up having to flash Lineage, as there was some outrage
| that in a highly limited set of circumstances, thin see-through
| T-shirts became slightly more see-through and OnePlus disabled
| that camera in their later firmware updates.
| chankstein38 wrote:
| You have to love when amazing innovations disappear just in
| case the lowest-quality rung of our society might misuse
| something... I'm pretty sick of being ruled based on the
| lowest common denominator.
| sirtaknt wrote:
| Some phones had near-IR camera (Pixel 4, Samsung S10)
| accessible via API. No "killer app" was found since then, 5+
| years
| ACCount37 wrote:
| iPhones also have a near-IR front camera, but that one is
| fully slaved to the FaceID system. Don't think anything in
| userland can access raw data from it.
| grgergo wrote:
| There are lots of 3D scanning apps using "Face ID", like
| Heges: https://hege.sh/
| ACCount37 wrote:
| Those rely on the depth maps, which can be accessed from
| userspace. But the depth maps are derived from IR camera
| footage, which is not accessible.
|
| Ironically, older iPhones have better depth resolving
| capability overall. Apple sacrificed depth sensing
| performance in favor of smaller unit size in the newer
| ones.
| seemaze wrote:
| I know many full size cameras have filters to specifically
| remove IR and UV from the images. Is this true for smartphones
| as well?
| ACCount37 wrote:
| Yes.
|
| CMOS image sensors are naturally sensitive to near IR. Early
| feature phones had no IR filters on their cameras - you could
| see an IR remote light up through them. But as people became
| more and more obsessed with smartphone camera quality,
| smartphones started to ship with those filters too. You get
| more "lifelike" colors that way.
|
| Although in some multi-camera smartphones, one of the
| secondary cameras may lack an IR filter.
| Tade0 wrote:
| One of mine definitely lacks such a filter because I was
| able to catch not only the remote, but also an electric
| stovetop while it was still heating up and its glow was
| barely visible with the naked eye.
| zubiaur wrote:
| Back when I was in oil and gas, we were thinking of using
| modified mirror less cameras without and IR filter for
| vegetation density calculations. There were a few vendors that
| sold the UAVs and modified cameras.
|
| Nowadays, there is a more mature ecosystem, with specialized
| drone mapping cameras tailored for the purpose.
|
| For our use case, the micasense rededge would have been
| perfect.
| chankstein38 wrote:
| Same! I want to be able to capture more of the spectrum
| already!
| sirtaknt wrote:
| I don't understand how from 3 independent values per pixel (RGB)
| they claim to derive 200+ independent values per pixel. Unless
| they are assuming a smooth "image" (all pixels the same RGB),
| perturbed only by the color card? Not exactly a camera then
| ladberg wrote:
| They're not claiming to get that many values per pixel, they're
| getting that many values overall for the medium through which
| light passes between the card and the phone. The idea light
| comes from a source (e.g. sun), bounces off the various colors
| of the card and thus produces hundreds of different spectra,
| those all pass through a medium, and land on the phone camera.
| So you're getting one measurement consisting of hundreds of RGB
| values that each represent intensity of different spectra, and
| you combine it all together to get a single spectrogram.
| esafak wrote:
| This could improve chromatic adaptation of captured images. In
| other words, better results when changing the white point.
| chaboud wrote:
| Funny enough, that's what photographers are doing when they
| shoot a color checker chart (e.g., Munsell, Macbeth, X-Rite).
|
| White balance is hard, in part, because the sensitivity bands
| of our vision and the camera sensors do not align. Take a look
| at fluorescent (or, better still, sodium vapor) light spectra
| for clarity on why this is a massive pain.
| mvhv wrote:
| This doesn't really seem like "hyperspectral imaging". I think
| the idea is having a reference colour chart of known emission
| characteristics and photographing it through a transparent
| substance gives you an idea of how much that substance attenuates
| each wavelength.
|
| It's a cool trick if it works, but it seems very finicky and I
| guess would be limited to transparent/homogeneous liquids?
| crazygringo wrote:
| In theory maybe you could build a version made of inks printed
| on a reflective mirror? And then you would hold the mirror so
| it reflected the object into the camera?
|
| But that seems far more difficult. Precisely combining and
| applying combinations of inks to a mirrored surface sounds like
| a helluva manufacturing challenge.
| aDyslecticCrow wrote:
| This is really cool and very clever. But i want to raise one
| thing.
|
| > designed a special color reference chart that can be printed on
| a card
|
| My rudimentary understanding of physics makes me suspect this
| sentence is a simplification.
|
| A normal printer use Cyan Magenta Yellow Black to print. A photo
| of such a print would already destroy alot of spectral
| information for the same reason the individual rgb sensors do.
|
| So i suspect those colored dots are a very careful and deliberate
| concoction of very particular inks with very specific spectral
| color bands.
|
| I suspect alot of effort went into finding, mixing and
| algoritmically combining the right inks.
|
| I'm guessing it works similarly to a how a narrow band florescent
| lamp makes only materials that reflect a very specific frequency
| be visible, which makea alot of prints and pigments look wierd.
| (If you do the opposite; use ink with very specific spectral
| band, you can instead measure the lamp)
|
| Insanely clever. (Whatever they did)
| kelseyfrog wrote:
| Not just that, but it would presumably be sensitive to light
| emission spectra too. As inks can only reflect wavelengths of
| light that hit them, if the emission spectra has spikes or gaps
| - think LED or florescent - the reflected spectra will be a
| function of the light source[1].
|
| Perhaps there's some accounting for this, and I'm curious to
| learn what it is, because it's a phenomenally complex problem.
|
| 1. You might think the sun is a standard source, but it's
| usually modulated by the atmosphere[2].
|
| 2. Unless you are in space.
| aDyslecticCrow wrote:
| > Perhaps there's some accounting for this, and I'm curious
| to learn what it is
|
| The slip itself is a calibration reference, so a clean photo
| of it could serve to compensate for the lamp and camera and
| calculate how accurate the readings is for different parts of
| the spectrum. (But good wide spectrum light would be ideal
| for high precision readout)
|
| You're also still limited to visible light because of the
| camera uv and ir filter, for which the sun is a decent
| reference.
| kelseyfrog wrote:
| oh, yes of course! Thank you :)
| RicoElectrico wrote:
| Printing can use so-called spot colors.
| dylan604 wrote:
| I similarly thought that just because they said print does
| not mean it was printed on someone's ink jet. I'd hate to see
| how many different Pantone colors might be necessary.
| altairprime wrote:
| If you only need one card per 10,000 photos, then the cost
| of the card starts to look cheap compared to a spectrometer
| and its bulk.
| privatelypublic wrote:
| Ink is perfectly capable of being a phosphor, in which case
| it'll up or down convert wavelength X to wavelength Y.
| aDyslecticCrow wrote:
| My gut feeling is that finding enough very specific
| wavelength shifting inks would be harder. Perhaps its a mix
| though to get good readings in the faar edges between the rgb
| wavelengths.
|
| I hope there is a research paper on this i can read.
| chankstein38 wrote:
| Wouldn't it be nice if they just told us so we didn't have to
| speculate? This is cool stuff and I'm glad I know about it but,
| as someone interested in this field of study, I'd love to try
| this out. But I guess I should stop being surprised when even a
| company like IEEE can't be bothered to write an article with
| any actual information. Just a bunch of simplified summarized
| crap.
| tzs wrote:
| At the bottom of the article is a link to the paper, which is
| open access.
| unglaublich wrote:
| Patent-pending... again someone trying to rent-seek a high-school
| physics fair idea. Measuring light absorption with a camera is
| almost as old as the camera.
|
| Using a known reflectance chart in-scene to recover spectral
| information is a standard calibration technique.
|
| What "investment" is patent law protecting here?
| aDyslecticCrow wrote:
| What you're referring to is color calibration. This is
| spectroscopy. This is likley more of a chemistry paper than a
| engineering paper because the ink in the reference chart is
| doing some heavy lifting.
| linsomniac wrote:
| Someone needs to build a phone that is leaning towards a
| tricorder; I'd buy that for myself and my kids. My Pixel 10 has a
| temp sensor on it, which is cool, but I've had minimal use so
| far.
|
| I've always wanted to build a tricorder with my son, was just
| thinking about it last week when he was putting together a
| digital compass (with RasPi Nano, magnetic sensor, GPS, and LED
| light ring + OLED).
| shrike wrote:
| Take a look at the phyphox app - https://phyphox.org/
| horacemorace wrote:
| Wow! That app is amazing thanks for sharing
| dtj1123 wrote:
| This is brilliant.
| lawlessone wrote:
| Caterpillar has a smartphone with a thermal camera. The price
| isn't far off the the price of the most expensive smartphones
|
| https://cat.smartwalkie.com/store/products/cats62pro
| dylan604 wrote:
| how does Cat's self repair policy compare to John Deere's?
| Then again, it's not far off from Apple's
| eichin wrote:
| There are also cheap ($200-$400 range) usb-c thermal cameras
| specifically for phone use (they're cheap because they're
| _just_ a sensor, the app on the phone is the "screen" and
| controls.) Great for narrowing down overheating hardware, and
| you can keep one in a pocket.
| abeppu wrote:
| I notice the article doesn't say anything about accuracy. This is
| not my area, but I think the _other_ hacky way to try to do
| spectroscopy with a phone is with a diffraction grating (and
| maybe a box with a slit in it). Diffraction gratings are cheap,
| probably not so different from a specially-printed reference
| card. If you have a choice, which is better?
| csmoak wrote:
| diffraction grating wouldnt give you a controlled lighting
| environment (illuminant). they seem to handle that issue here
| by using a known spectral reference chart which might let them
| handle any normal lighting environment.
| abeppu wrote:
| I would think in the same environment you would take images
| immediately before and after adding the sample.
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