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!
Google’s branding is awful.
Man, we're so bad at naming, that we keep joking about it... And trying to satire that with internal codenames (the ones engineers give without adult supervision)... And somehow those often seem better than the external names :(
This is something we'd have to separately test, and ultimately make a wholly different app for if it's feasible on iOS.
What would be really helpful is a database of apps, similar to the WINE project, maintaining how well they work on a de-googled phone, with a table, columns being "no root", "rooted", "with microg", etc, and a WINE style rating of how well it works and what problems you'll run in to.
You would know which banking services, etc don't work well or at all and could choose your establishments with foresight.
What were your biggest reliance on Google services you found in this 1 year and how did you overcome it?
However there is a clear bottleneck with the Google AR team for features that the community really wants. While it's understandable, perhaps the open source libraries aren't the priority or there's short staffing, there are issues like this one - https://github.com/google-ar/arcore-android-sdk/issues/153 - that have been open since Jan 2018. This one asks that we can use the smartphone flashlight simultaneously with ARCore, but there's no visibility on how close we are at the moment. This feature would have likely improved our work's performance greatly, but even in general, many other AR developers are asking for it.
Re: overcoming it, there's not much we can do in this case. We just didn't implement the feature.
Long standing issues/feature requests are typical of Google's Android ecosystem, Regardless I eagerly await for your release. I think ToF based spy-camera detection could make a great addition to the women safety apps in India.
You've got a community of people who're willing to spend time polishing.
It'd be a massive benefit to society to make this widely available.
Single pixel cameras are lensless, for instance.
> many early "stealth" radar detectors were equipped with a radar-detector-detector-detector circuit, which shuts down the main radar receiver when the detector-detector's signal is sensed, thus preventing detection by such equipment.
https://en.m.wikipedia.org/wiki/Radar_detector#Radar_detecto...
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.
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.
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?)
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.
Not all of them are lasers, which might be important.
As you say though, extra heat is a physical guarantee, so maybe a smarter technique exists to separate signal from noise in the thermal domain that I don't know of yet.
https://en.wikipedia.org/wiki/One-way_mirror#Principle_of_op...
Metamaterials have a chance at at: https://www.nist.gov/news-events/news/2014/07/new-nist-metam...
Counter-counter surveillance techniques, IIUC.
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.
what technology advancement would be needed to increase the detection rate and reduce the false positives?
- 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
Great project btw!
If you have a projector, you can do more. I believe Apple uses a flash, which has a low resolution, but is perhaps less cpu-intensive and less error prone, although it has a lower resolution. That would be a real Lidar, which is an active measurement. Of course combining that with sensible stereoscopy nets better results.
ToF stands for "time of flight". It works exactly by measuring how long the signal takes to go from camera to object and back [1]
Stereoscopic cameras are another type of 3R camera, they are not ToF and they are not active.
Each has pros and cons.
Most other ToF sensors use "indirect" ToF, where they measure the phase difference between incoming and outgoing signals to derive distance.
However, it gets murky as cheap 2D LIDARs on say, robot vacuum cleaners, use geometric techniques to find distance (basically return angle of a reflection). I explored this in a previous work.
TLDR: I would recommend not taking any naming at face value and reading the actual datasheet or more commonly, technical marketing materials, since few ToF manufacturers that I see have a public datasheet.