Welcome, Guest. Please login or register.
April 19, 2024, 12:43:50 AM

Login with username, password and session length

Search:     Advanced search
we're back, baby
*
Home Help Search Login Register
f13.net  |  f13.net General Forums  |  General Discussion  |  Serious Business  |  Topic: SCIENCE! 0 Members and 1 Guest are viewing this topic.
Pages: [1] Go Down Print
Author Topic: SCIENCE!  (Read 4356 times)
Viin
Terracotta Army
Posts: 6159


on: March 31, 2016, 06:28:31 PM

Since we don't have a general purpose SCIENCE! thread, well, here you go!

I ran into this listening to the TED Radio Hour podcast..

Capturing sound from object vibrations (random bag of chips!):
https://www.ted.com/talks/abe_davis_new_video_technology_that_reveals_an_object_s_hidden_properties?language=en



Imagine using a security video feed to reconstruct the conversation in a room, simply by analyzing the movements of a random nearby object.

- Viin
Goreschach
Terracotta Army
Posts: 1546


Reply #1 on: March 31, 2016, 06:55:03 PM

Imagine using a security video feed to reconstruct the conversation in a room, simply by analyzing the movements of a random nearby object.

Literally impossible. The nyquist limit of the video framerate would prevent sampling of the typical vocal range of human speech.

Haven't even watched the video yet, but I'm assuming they were using hi speed cameras, like the ones mythbusters use sometimes, to record with.
MahrinSkel
Terracotta Army
Posts: 10857

When she crossed over, she was just a ship. But when she came back... she was bullshit!


Reply #2 on: March 31, 2016, 07:04:30 PM

Yeah, you need a sampling rate at least twice (and more practically 4x) that of the frequency you are trying to record. Since for standard cameras that is 60 frames per second, you're short an order of magnitude of what you would need to reconstruct a voice (human voices range from 80-250hz).

Not to mention that even 4K resolution probably wouldn't be adequate unless the resonant membrane was extremely close to the camera. Easier just to have a microphone.

--Dave

--Signature Unclear
Furiously
Terracotta Army
Posts: 7199


WWW
Reply #3 on: March 31, 2016, 07:07:41 PM

Something like a laser and a window??

Viin
Terracotta Army
Posts: 6159


Reply #4 on: March 31, 2016, 07:49:22 PM

Sorta like a laser and a window, but different. Watch the video before you start spouting about things you don't know ;)

- Viin
MahrinSkel
Terracotta Army
Posts: 10857

When she crossed over, she was just a ship. But when she came back... she was bullshit!


Reply #5 on: March 31, 2016, 08:30:47 PM

Sorta like a laser and a window, but different. Watch the video before you start spouting about things you don't know ;)
3:30 in the video: "What if we record them with a high speed camera?"

EDIT: Later he talks about using a standard camera, but the audio they are getting is so distorted that it doesn't sound like anything at all. And all of this is with the cameras zoomed in on very good resonators (chip bags, maybe a fake plant).

EDIT2: The structural analysis and CGI potentials are actually interesting, as is the idea of reading bio-signs from standard video (a camera that could detect apnea in infants could be the first major counter to SIDS). But the 'surveillance' potential is practically nil compared to what equivalent processing could do with even poor quality audio.

--Dave
« Last Edit: March 31, 2016, 08:48:54 PM by MahrinSkel »

--Signature Unclear
Viin
Terracotta Army
Posts: 6159


Reply #6 on: March 31, 2016, 08:39:56 PM

Keep watching.

- Viin
Yegolev
Moderator
Posts: 24440

2/10 WOULD NOT INGEST


WWW
Reply #7 on: December 16, 2016, 07:44:15 AM


Why am I homeless?  Why do all you motherfuckers need homes is the real question.
They called it The Prayer, its answer was law
Mommy come back 'cause the water's all gone
Pages: [1] Go Up Print 
f13.net  |  f13.net General Forums  |  General Discussion  |  Serious Business  |  Topic: SCIENCE!  
Jump to:  

Powered by SMF 1.1.10 | SMF © 2006-2009, Simple Machines LLC