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FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

fingerio.cs.washington.edu

61–70 of 126 posts

Re: FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

#63
post #55

I wonder how accurate it really is. The demo video didn't match up with the movements at all and the on-screen drawings looked like prerecorded video that they were trying to sync to. It's a neat idea, but without a dedicated component or an extremely high-speed RTOS, you're not going to come close to the level accuracy that's really needed to do the math and still allow interaction. I don't mean to rain on the parad…

To me it looked like a ton (two seconds or so) of latency, not pre-recorded video. And I would expect latency for such heavy DSP work on a phone.

This is correct. The movements match up just fine, but the reaction time there is something above 2 seconds.

Re: FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

#65
post #13

Earlier quoted context omitted.

it's obviously pretty different when you don't have to be touching the phone to interact with it

Not when it's a few inches away. It's less distance than voice interaction.

A lot of people are a few inches from my pocket every day. And I can easily imagine software listening for such sonars and sending back fake responses. I think debarshri has a valid point.

Re: FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

#67
post #55

Earlier quoted context omitted.

To me it looked like a ton (two seconds or so) of latency, not pre-recorded video. And I would expect latency for such heavy DSP work on a phone.

This is correct. The movements match up just fine, but the reaction time there is something above 2 seconds.

They need to buffer to get a Fourier transform and to do the autocorrelation.

Re: FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

#68
post #15

I wonder how much power all the processing draws. Judging from the slow movements and the delayed update on the screens in this video, it's pretty heavy on the processor.

They are calculating autocorrelation and a Fourier transform so they need to buffer the data. Two seconds is probably the shortest buffer that works reliably.

Re: FingerIO: Using Active Sonar for Fine-Grained Finger Tracking

#70

I work with sonar and the physical positioning of the sensors is important in trying to get useful results. Why is it these academic types don't release the apks or software? Just publications and maybe a video.

Did you ask? Many years ago I decided to reproduce an algorithm used to detect copy/paste image modification.

http://blog.jgc.org/2008/02/tonight-im-going-to-write-myself...

The researcher was happy to provide me with their test images to verify that my implementation worked. Try asking.

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