[HN Gopher] Spy camera detection using smartphone time-of-flight... ___________________________________________________________________ Spy camera detection using smartphone time-of-flight sensors Author : Nirali_Feige Score : 421 points Date : 2021-11-18 16:21 UTC (6 hours ago) (HTM) web link (dl.acm.org) (TXT) w3m dump (dl.acm.org) | ww520 wrote: | Does the app take pictures to find the lens? Or videos? | frizensami wrote: | It's analyzing the camera feed in real time, so more like a | video. | ww520 wrote: | Good to know. Yes, continuous video feed is easier to spot a | light source. Can do differential analysis. | qwertox wrote: | Here's a demo video [0] of the app. It is embedded in the | author's website [1] | | [0] https://www.youtube.com/watch?v=AFjGQNaqmXA | | [1] https://sriramsami.com/research/ | HackOfAllTrades wrote: | A stand-alone Single-Point LIDAR might be used to remove the | high-end phone requirement. Should interface to a phone USB port | with a simple UART/I2C-USB adapter. Search Amazon.com for | LIDAR finds 'Lidar Range Finder Sensor Module TF-Luna, Single- | Point Micro Ranging Module 0.2 to 8m Compatible with Pixhawk, | Arduino and Rasppbarry Pi with UART / I2C Communication | Interface' $25. And 'MakerFocus TFmini-s Micro Lidar Module | 0.1-12M Lidar Range Finder Sensor Obstacle Avoidance Sensor Tiny | Module 1000Hz Single Point UART I2C IO Compatible with Pixhawk Ar | duino and Raspberry Pi' $39. The 2nd one is waterproof. | HackOfAllTrades wrote: | Also on Amazon 'Worldoor CC308+ Multi-Detector Full-Range All- | Round Detector For Hidden Camera / IP Lens/ GMS BUG / RF Signal | Detector Finder , CC308 + detector hidden mini camera/IP | camera/general manager/radio frequency signal detector | instrument' <$20. | | And several similar hidden camera detectors. I have no idea how | well/badly this sort of device works. | anthomtb wrote: | The acronym should be removed from the HN title. LAPD does | nothing but sow confusion when used as the first word here. | frizensami wrote: | Author here, sorry, I didn't post this (but it is the paper's | title). Hopefully it gets corrected. | [deleted] | errcorrectcode wrote: | Molka is/was a problem in Korea. I wonder how it compares to | SpyFinder Pro which seems like it's 95%+. | | https://www.kickstarter.com/projects/spyassociates/spyfinder... | max47 wrote: | that kickstarter campaign is borderline a scam. They have an | msrp of 400$ for a Chinese gadget you can by for <10$ online. | And no, their LEDs are not special and you can source better | ones from digikey for less than 1$. | djmips wrote: | Borderline. You are being charitable. | frizensami wrote: | Good question. We evaluated the "K18" hidden camera detector, | and not the SpyFinder, but they use an identical principle. | schleck8 wrote: | While it's especially bad of a situation in South Korea, it has | become a serious issue globally. | | > The same poll found that one in 10 guests (11%) had found | hidden cameras in an Airbnb rental. | | https://www.forbes.com/sites/suzannerowankelleher/2020/01/27... | cf100clunk wrote: | "Tiny hidden spy cameras concealed in sensitive locations | including hotels and bathrooms are becoming a significant threat | worldwide." I think motel room tenting and indoor foil-wearing | might seem to be more justifiable, less paranoiac. Who knew? | woeirua wrote: | I wonder how hard it would be to engineer a material that you can | put on top of the hidden camera lens that would greatly diffuse | the specific frequency range of light that these ToF sensors use | while permitting mostly visible light through? If so, it might be | possible to defeat this approach relatively easily. | | Looking at what the DL filter is doing, I wonder how well this | really generalizes. It seems that many of those examples are | virtually indistinguishable to a human (hence the high false | positive rate for the naked eye experiments). | jcun4128 wrote: | Bring a 360 degree projector, up the ante | frizensami wrote: | w.r.t the material, it seems to be possible, since ToF sensors | operate in a narrow 850 nm band. However, I don't know if a | coating can be made that also doesn't overlap with the visible | light range since 850 nm is somewhat close to red light, or | whether that would be cheap if so (given that the hidden | cameras themselves are only $1 at the moment). | | I also have similar reservations about the DL approach in | general. What makes me more confident is that we trained on a | relatively small number of objects (~10) and tested on a | totally different set of 30 objects. We're also using very | small regions-of-interest as inputs (5x5), so there's little to | no overfitting on the environment or objects themselves. | hyperstar wrote: | What are the best ways of doing this without a smartphone? | frizensami wrote: | The free option: use your smartphone's flashlight and try to | spot unnaturally bright / colored reflection. | | If you want to spend some money and don't mind carrying an | extra device: probably any of the "hidden camera detectors" on | the market will be at least somewhat useful. K18, CC308+, etc. | | We're trying with our work to get better or at least equivalent | results without having to use external devices. | [deleted] | benbojangles wrote: | similar technology exists on ebay for under $5, you plug it into | the phone's usb port and it emits ir led lighting and back into a | lens | chris_wot wrote: | Can you supply a link to one of these devices? | aaronax wrote: | This reminds me in a way of the yacht with a system that detects | cameras taking a picture of the yacht and sends a beam towards | the camera to wash out the image. | | https://petapixel.com/2012/10/28/worlds-largest-private-yach... | frizensami wrote: | Pretty interesting idea. In fact, there are a number of | military-related systems to spot sniper scopes (generally | optics) with lasers, which I expect is similar to what they | used here. | iseanstevens wrote: | Clever! Thanks :) | victoraaa wrote: | fdsd | coretx wrote: | Did the Rubidium price go up already ? ;-) | jeffbee wrote: | I'm having a hard time seeing how the obsolete and not exactly | tiny OV2640 was crammed into that electrical plug. The integrated | module is a 10mm cube with a 1/4" lens and to be useful it needs | a power supply and either a storage controller or wireless | network interface. | frizensami wrote: | We just used the OV2640 module itself | (https://www.aliexpress.com/i/4000036275403.html) which is | pretty small. While we didn't actually include a little battery | and perhaps something like an ESP-32 to control it, I'm pretty | sure those could fit inside the plug if hollowed out. | SubiculumCode wrote: | LAPD is not the Los Angeles Police Department, despite what we | all were thinking. | [deleted] | micahcc wrote: | Ok I'm not crazy | abfan1127 wrote: | what is it? | throw_away wrote: | > To answer this question, we propose LAPD (Laser- Assisted | Photography Detection) | simonebrunozzi wrote: | I would be curious to know what would be the best method/tool to | detect hidden cameras in places you visit (e.g. hotels, AirBnBs). | I looked for devices on Amazon.com and found nothing that seems | to be really good at detection. | [deleted] | elric wrote: | So, could this be used to find better hiding spots for hidden | cameras? | [deleted] | frizensami wrote: | Yeah, that's fair. If someone really wanted to do this though, | they could also just use existing products like this one: | https://www.amazon.com/Worldoor-Multi-Detector-Full-Range- | Al.... | DennisAleynikov wrote: | absolutely, at least against this method of detection | dclowd9901 wrote: | Maybe, but realistically, since the sensor uses the properties | of a camera lens to detect the camera itself, I would have to | bet there is little that could actually be done to obscure the | hidden camera and also still get a usable image from it. This | is a pretty brilliant detection method. | nybble41 wrote: | It might be easier to design the room to create false | positives and undermine trust in the detectors. Assuming you | have that kind of influence, anyway. That's not an option if | you're just trying to plant a camera in an existing room. | | I assume minimizing the aperture would be a fairly reliable | way to avoid detection. A pinhole camera would be hard to | find by any optical technique, though the video quality would | suffer. Perhaps one could project through a pinhole onto a | screen and record the projection, so the sensor is angled | away from the room? | frizensami wrote: | That's an interesting idea: trying to create so many false | positives that the user gives up. We're already removing | around 100+ false positives per frame at the moment in | difficult cases, so perhaps it's possible to overwhelm the | filters with very maliciously designed environments. | | I think the easier way would be to hide the cameras in much | harder-to-reach places so that it's inconvenient for the | user to get their smartphone near. This might reduce the | kind of videos that can be taken, but maybe an attacker | will find that a reasonable tradeoff. | djmips wrote: | Probably the very smart spy camera can detect off axis | TOF artificial light and close a shutter over the lens. | Assuming your app integrates over the scanning motion, | the camera won't be detected while it's shutter is | closed. After the illumination is completed the spy | camera can re-open it's shutter. | | The spy camera could also something like your system to | detect the phone camera and take defensive measures. | frizensami wrote: | Yes, perhaps. At the very least, adding a variable | shutter and extra logic will drive up the price of the | camera, which will be some consolation. | raldi wrote: | "Specifically, the hidden camera [...] reflects the incoming | laser pulses at a higher intensity than its surroundings due to | an effect called lens-sensor retro-reflection. This occurs when | almost all light energy impacting an object is reflected directly | back to the source" | polishdude20 wrote: | Given this, can you just hold up a flashlight right next to | your head and look around the room for bright spots? | frizensami wrote: | This is actually one of the recommended methods if you have | no other options. It's not particularly good otherwise | because of the limited visibility cone of the hidden camera | reflections. From experience, the flashlight often tends to | occlude the reflections you want to see, or the user isn't in | the right place to see the reflections (near the flashlight). | gpt5 wrote: | That's exactly how detection tools work today. | | Here is a random one: | | https://www.lexuma.com/products/lexuma-xscan-portable- | hidden... | xipho wrote: | Likely. Headlamps are well known tools for collecting spiders | at night, when positioned just right they will reflect off | the spider's eyes as you move your head around. It's an | amazing thing to see spiders _everywhere_. | brokenmachine wrote: | Thanks for giving me nightmares. | lapetitejort wrote: | For peace of mind that sounds like the _worst_ tool to use. | pasker wrote: | I remember we were spotting alligators at the Amazon river | with flashlight and their eyes reflections :-) | gorgoiler wrote: | It is _the_ standard way of detecting concealed lenses. | | Random google result: | | https://www.pimall.com/nais/startfinder.html | rtkwe wrote: | The light returns pretty directly to the source which is why | most devices designed to use that detection method have the | illuminators around an eyepiece so there's less distance | between the illuminators and your eye. | micahcc wrote: | It took me a full minute to realize this wasn't the Los Angeles | Police Department's R&D division | [deleted] | chris_wot wrote: | What I would like to know is - how do you detect who is using an | IR blaster? | samstave wrote: | If there was literally ANY metric I would want in a HUD; 'How | many cameras are viewing me now, and where are they' has got to | be the top of the list... | jcun4128 wrote: | > system that leverages the time-of-flight (ToF) sensor on | commodity smartphones | | I think only the high end iPhones/iPad have these type of cameras | right now right? | | I'd also be curious about the exact angle you have to hit to get | a reflection | | Probably wouldn't work but bright flash in a room? | frizensami wrote: | Great question about the angle actually. There's previous work | by an applied physics group [1] that shows the detectable | field-of-view from the camera is about 20 degrees. Our | experiments also confirm that. | | We also think using the smartphone flashlight (if that's what | you mean) is the best way forward. That's already very helpful | (and recommended) for humans to find hidden cameras, and it | should be a useful extra modality for our work too. | | [1] https://ieeexplore.ieee.org/document/8790792 | jcun4128 wrote: | You don't have to answer but, I'm assuming by the phone's API | you can steer the beam/have an exact precision known of the | minimum angle you can sample? That's pretty cool tech to work | with. | frizensami wrote: | Unfortunately we can't steer the ToF beam, so the user has | to move the phone around to multiple positions (a 2D grid | of positions, basically). The app provides pretty clear | guidance on where to move the phone to cover all possible | spots, though. | semi-extrinsic wrote: | My Huawei P30 Pro from 2019 has a ToF sensor, so I don't think | it's very uncommon? | jcun4128 wrote: | Yeah I guess my phone is not in that tier... it looks to be | marked up 2x from GSMArena's prices... but $150 vs. $350 | pricing. Also the Moto G Stylus (my phone) is from 2020 | frizensami wrote: | Yep, there are a pretty decent number of smartphones with it, | and I think the trend is moving in the right direction | (iPhone 12 Pro had it and Apple included it in the iPhone 13 | Pro too). | z3t4 wrote: | If the spy camera has infrared leds then you can detect those by | removing the infrared filter from a camera, can be done on some | smartphone cameras programmatically I think. | Scoundreller wrote: | In a dark room, you can point an old-style remote control at an | iPhone camera and see button presses light up the IR | transmitter. | | I do this to test their batteries :) | | But older Cell-phones (flip phones) with CMOS sensors used to | be really good at this as they wouldn't filter much IR in order | to work better in low-light conditions. | SubiculumCode wrote: | I was really hoping that they had an app I could install, as they | implemented LAPD on Android. | frizensami wrote: | Hey! Author of the work here. We just finished presenting this | at a conference yesterday, so we're working on open-sourcing | the code now with some feedback from the community. It's got | some warts because of API limitations (no way to automatically | align color and ToF cameras, so we're manually doing that). | SubiculumCode wrote: | Cool work. It would be great for scanning hotel rooms. | frizensami wrote: | Thank you! | rbanffy wrote: | You'll still need the laser emitter. Here I would hope the | emitter can be operated in a high-power small-target mode to | also obliterate the detected cameras. Extra points if it can do | so autonomously - I leave it over the bed, go out for dinner, | and come back to a room without any cameras. | [deleted] | jaywalk wrote: | You have to go to the second page of the full PDF to even see | what LAPD stands for, which is Laser-Assisted Photography | Detection. They need to be more mindful of this, especially when | they made up the acronym themselves. | intrasight wrote: | Cool tech. Too bad about the paper title. One should never use | a novel acronym in an academic title IMHO. | w0mbat wrote: | LAPD is worse than novel, it is already used in another | context where it is very well known. | | Most people will already know this, but LAPD = Los Angeles | Police Department, often featured in TV shows, films and the | news. | ska wrote: | > Most people will already know this, but LAPD | | s/most people/most americans/ | | plus some non americans of course, but it's not a global | association by any means. | elzbardico wrote: | The authors are from Singapore. The association is not that | direct for non-americans. Actually, I only noticed it after | several people mentioned it here. | PeterHolzwarth wrote: | 95.75 percent of the planet is not American, if you are | partially referring to the acronym of the police department. | haswell wrote: | Regardless of this, it's generally good form to define an | acronym the first time it's used, even if there was no | duplication/overlap. | | With that said, while you're correct: | | - A significant portion of tech advancement is US-centric, so | I understand the instinct to ask for clarification | | - I'd argue that the LAPD is relatively well-known world- | wide, much like the RCMP, or RAF, or other very famous | organizations | Jolter wrote: | Well, you just got me to Google "rcmp". That's just one | data point of course, and I was indeed aware of their | informal name from popular culture. | [deleted] | [deleted] | fortran77 wrote: | I was working on a project like this and we relied on the fact | that the IR filter on most cameras was a retro reflector. Remove | the IR filter and the camera will be harder to find. I think the | technique here also depends on the IR filter's characteristics. | frizensami wrote: | That's a good point. I'm not sure how the removal of the IR | filter will affect this work. I mentioned some prior work from | the physics side [1] in another comment that explores the | reflection characteristics in more detail. I don't think they | explored the IR filter contribution as well, so this could be | an interesting direction. | | [1] https://ieeexplore.ieee.org/document/8790792 | sturgl wrote: | IR cut filters used in smartphone-style cameras are typically | reflective. | | Installing an absorptive IR cut filter on top of the lens | would decrease the amount of reflected light, and might | hinder your approach. Those are pretty cheap to buy, so you | could try it out pretty easily. | injidup wrote: | I know a woman who discovered a hidden camera in the female | toilet at work disguised as some kind of utility hook on the | door. Cheap to buy on amazon!! The SD card inside had pictures of | the company owner's desk but not an actual picture of him. The | police declined to prosecute because of lack of evidence. | xanaxagoras wrote: | Gross. | stronglikedan wrote: | > The police declined to prosecute because of lack of evidence. | | Thank goodness! Imagine being convicted of a crime because some | perv took some pictures of your personal stuff in an attempt to | frame you. | spoonjim wrote: | Prosecute and convict are different. You should at least pull | his credit card transactions and see if he recently bought | it. | jjcon wrote: | That would still be circumstantial wouldn't it? | mywittyname wrote: | Lots of evidence is circumstantial. | | Contrary to popular believe, circumstantial evidence is | not bad evidence. In isolation, it might not be enough to | convict, but when used in conjunction with other | evidence, it can create a damning case. | | 1. The camera contained pictures of owners desk. | | 2. That model camera was purchased on amazon by the | owner. | | 3. The serial number of the camera indicates that it was | sold on amazon and produced around the time of purchase | by the owner. | | 4. The camera was found in a place the person had | reasonable, unrestricted access to. | | 5. owner was found in possession of pictures that look to | have been taken by the device, in the position where the | device was originally discovered. | | * I'm not asserting these facts are true, just stating | them for the sake of example. | | In isolation, each of these pieces of evidence don't | prove much, but in totality, it is highly unlikely that | all of those things would happen to an innocent person. | Jury's don't need to be 100% certain to convict, they | need a preponderance of evidence. | | I can see why a prosecutor wouldn't pursue this case | against a rich person though. The police are unlikely to | do a good job at collecting evidence, a good lawyer will | get enough of it thrown out, victims probably won't want | to testify anyway, and being a business owner, this | person might have clout with local politicians who will | make trouble. | GekkePrutser wrote: | Sounds like that scene from Austin powers :) where he | keeps saying the pump isn't his. | | But you're right that's pretty damning. | HWR_14 wrote: | I mean, if you showed him buying the same model from | Amazon and it had pictures from him testing it in his | office, that's probably enough to convict. | rtkwe wrote: | Individual pieces of evidence are often circumstantial, | taken together they're enough to prove something. | moron4hire wrote: | Most evidence is. "Circumstantial" doesn't automatically | make the evidence useless. | IIAOPSW wrote: | Yes, which is insufficient for a conviction but | reasonable suspicion to get a warrant. | dzhiurgis wrote: | Add fingerprints and DNA from SD card, logs on PC... | [deleted] | mike-cardwell wrote: | To be fair to the owner, that would be a good way of setting up | somebody else to take the fall if the camera was discovered. | frizensami wrote: | Hey! Sriram here, author of this work. I'd be glad to answer any | questions. There's also a short talk I gave about this here | (https://www.youtube.com/watch?v=t4Txdhlji4k) if that's helpful! | djmips wrote: | Would your system work against flat cams? | https://youtu.be/BdgwO_i5p54 | megablast wrote: | Does it work against something that doesn't exist yet?? | frizensami wrote: | Thats very interesting, first time hearing of it. Not sure, | really depends on what kind of reflection it generates when | light hits it, and because of the unique design I'm not sure | what that will be. | deegles wrote: | What are the properties of the cameras that don't get detected? | Wouldn't bad actors just use the same app to check if their | cameras are detectable at installation time? | frizensami wrote: | So far the biggest issue is if the camera is angled oddly | away from the user (basically, outside the 20 degree | observable FoV). Another issue would be if they manage to | install a larger camera that returns larger reflections | (which we filter out). | | Regarding using the app to check, I guess that applies for | the existing handheld detectors as well. It's definitely | something that intelligent attackers can try to plan for, but | we havent tested the adversarial robustness of the system | right now. That would be a very interesting direction for us | as well. | frizensami wrote: | But at least for the larger camera case, we can just | increase one of the filtering thresholds for reflection | size, which is already doable on the UI | starwind wrote: | Do you have any plans release this as an app I could install on | my phone? | frizensami wrote: | Yes, we do! There are a couple of user-facing annoyances at | the moment, one of which I mentioned in another comment | (hacks to align the color and ToF images). Hopefully these | API limitations are removed soon, or we find better | workarounds. | david_allison wrote: | Would you consider open sourcing the app as-is? | | You've got a community of people who're willing to spend | time polishing. | frizensami wrote: | It's definitely something I'm considering. The only hard | blocker now is a hashmap that checks for our test phones' | unique ID and applies a fixed transform to align both | cameras. Right now, any other phones will cause an | immediate crash. Minimally I think we need to disable | this and maybe include a small UI to let users put in the | alignment parameters (just a scale + offset). | frizensami wrote: | Also I appreciate the interest, thank you. I'm heading | back from the conference over the next few days, so I | should be more free to take a look at it soon. | david_allison wrote: | Feel free to shoot me an email (in profile) if you'd like | this UI done. No need for anything else other than the | source code. | | It'd be a massive benefit to society to make this widely | available. | jmnicolas wrote: | If you do release it, is it possible to not depend on | Google services please? I am almost a year in my degoogled | life! | frizensami wrote: | I would love to, but I'm not sure how yet without a major | re-write. The augmented reality code we completely rely | on is part of Google Play Services for AR. I definitely | do understand the benefit of degoogling, so maybe it can | be a community effort once I opensource it. | seaman1921 wrote: | Please don't make the functionality worse just to please | the de-googled hacker=news crowd. | Iolaum wrote: | Awesome, if there's a waiting list or a website that we can | join or follow to be notified of a release please share. | frizensami wrote: | Sadly no project-specific page yet, but I'll definitely | update on my page at https://sriramsami.com/research/ (I | think there's an RSS feed?) when it's active. | specto wrote: | https://sriramsami.com/feed.xml | iamwil wrote: | Where do we sign up to be notified when this is released? | Mikejames wrote: | +1 | datameta wrote: | same here | 123pie123 wrote: | I do like this | | what technology advancement would be needed to increase the | detection rate and reduce the false positives? | frizensami wrote: | Right, a few things would be very useful: | | - Increasing the resolution of ToF cameras (right now images | are around 320 x 240) --> reflections from hidden cameras can | then be more detailed, whereas now it's only 1 or 2 pixels | each. | | - Increasing the bit-depth of ToF images - right now every | pixel is only 3 bits (8 colors). It's very hard to | differentiate bright hidden camera reflections from | everything else, so we had to do a lot of work for that. | | - API improvements in conjunction with augmented reality | libraries, e.g., a) allowing Android devs to enable the | flashlight when AR apps are running b) more raw access to the | ToF sensor if possible | debt wrote: | 320 x 240, is this the resolution of the depth data | provided by the LiDAR sensor? | frizensami wrote: | Yep, exactly. | pnw wrote: | Samsung started marketing their ISOCELL Vizion 33D camera | in 2020 with 640 x 480 resolution. So it's likely we'll | see better ToF resolution announced in some phones in the | next year or two. | | Great project btw! | frizensami wrote: | Thank you! Actually, my understanding when I started this | project was that I would get a 640 x 480 image (IMX516 | sensor). However, I could only get a 320 x 240 image from | the sensor through the Android API, so that was a bit of | an oddity. | datameta wrote: | The results are even more impressive with that | considered! | frizensami wrote: | Thank you! Hoping for higher resolutions soon. | 5faulker wrote: | The next project would be creating another device to detect | these spy camera detectors | stinos wrote: | A hidden camera which detects ToF sensors | 14 wrote: | I was wondering if cameras started using anti-reflective glass | would this prevent detection? Some of the glass I've looked up | say they reflect less than 1% of light. How sensitive is your | app could it detect 1% reflections? Thanks | nomel wrote: | It's lens + sensor stackup reflection. Camera sensors are | much more reflective than a lens. | 14 wrote: | So would something like anti reflective glass for light | coming into the camera then another layer of like tint that | will stop light from reflecting back out if the camera? Ya | I know that doesn't exist but That is because they were not | trying to do undetected as hard before. Just thinking of | counter surveillance techniques. | PaulDavisThe1st wrote: | > Just thinking of counter surveillance techniques. | | Counter-counter surveillance techniques, IIUC. | frizensami wrote: | Yep, the combination is highly reflective. I cited another | work (by a physics research group) in a comment that | modelled and tested this effect comprehensively. | 14 wrote: | Would you speculate if anti reflective glass on the | outside of the camera and a layer of one way tint on the | inside that would allow light through but prevent it from | reflective back out? I'm just thinking what we will | expect in the future to sell the "undetectable spy | camera". | frizensami wrote: | That's a great question. I'm not totally sure if this is | possible. If it was, I think one-way mirrors would use | this technology. For now, it seems like they only work | because they only let 50% of the light through + there's | a brightness differential between both sides. Perhaps | someone more informed about this could chime in. | ticklemyelmo wrote: | Could this be applied to longer-range applications? Concert / | theater cameras, camera / binocular observers, counter-sniper | detection? | frizensami wrote: | While the broader technique should work for those | applications, the platform (smartphone ToF sensors) probably | won't. Smartphone ToF sensors have a pretty limited range. We | were only able to detect cameras within 1 metre of the | smartphone because we're really using the hardware for | something it's not intended for. | | For the applications you suggest, there are some existing | military-looking devices out there that use multiple lasers | to find sniper scopes, for example. My basic searching shows | at least https://www.ldsystems.us/product/sniper-optics- | detector/#, though I'm sure there's more. | mensetmanusman wrote: | Great work! | | Do you have a link to where you can buy these types of time of | flight lasers/sensors? Curious about the additional hardware | cost versus sensitivity. | frizensami wrote: | Thank you! | | While this work operates on ToF sensors that are already | present in smartphones (e.g., Samsung S20+/Ultra), a | Microsoft/Azure Kinect should also be a valid option because | it has a depth camera as well. It has a higher resolution and | bit-depth as well. | | We initially intended to compare against the Kinect, but it | doesn't fit the use case (something that you can have on you | at all times). However, it could be a cheap choice for a | different kind of deployment (automated hidden camera | detection with robots, perhaps?) | tootie wrote: | So I had no idea phones have ToF sensors these days. Do | most phones have them or only the high-priced flagships? | What are the actual intended uses for them? | frizensami wrote: | High priced flagships have them but there are also a few | midrange phones like the Huawei P30 Pro that have them | too. The trend seems pretty positive towards more ToF | sensors in phones, especially because Apple has had them | for two iPhone Pros in a row now. | | They're basically for augmented reality applications | because they sense depth. Placing objects at the right | size and scale in the augmented view is much easier and | more accurate with the ToF sensors, for instance. ___________________________________________________________________ (page generated 2021-11-18 23:00 UTC)