Seeing Around Corners with a Mobile Phone? Synthetic Aperture Audio Imaging:
Seeing around corners, in the dark, and through smoke is difficult without specialized sensors[Velten et al. 2012], and so far impossible with a mobile phone. We use an active audio system to sense objects around occluders. Current techniques perform passive localization of sound sources with a microphone array, however, we demonstrate that with one microphone and one speaker pair, such as the ones found in mobile phones, it is possible to sense the specular
reflection of silent objects such as mannequins around occluding objects. We demonstrate this technique by sensing a mannequin occluded by a wall.
Siggraph 2014 Poster, Student Research Competition, PDF: Hisham Bedri, Micha Feigin, Michael Everett, Ivan Filho, Gregory L. Charvat, and Ramesh Raskar. 2014. Seeing around corners with a mobile phone?: synthetic aperture audio imaging. In ACM SIGGRAPH 2014 Posters (SIGGRAPH ’14). ACM, New York, NY, USA, , Article 84 , 1 pages. DOI=10.1145/2614217.2614282 http://doi.acm.org/10.1145/2614217.2614282
Grid-Free time domain super-resolution for audio imaging:
The resolution of audio ranging and imaging is heavily limited by bandwidth. Here is an attempt to increase the resolution through continuous basis pursuit, a grid-less sparse algorithm. Comparison of backprojection, basis-pursuit denoising, and continuous basis pursuit shown.
PDF: Grid-Free time domain super-resolution for audio imaging: , Matlab Code: Code (readme coming soon)
Wrist-Wave: Context-Aware Clothing that listens to its environment:
When you hear music, your foot starts tapping. What if your clothes interacted with the music around you! The wrist-wave is a battery operated wearable LED display which changes patterns according to the music around you! Great for dance clubs! The next version will have motion control, any motion correlation in this video is a coincidence.
Orthographic Tensor Display Implementation:
Smoke Tomography for a floating 3d display:
Hearing the shape of a room: GUI/Simulator/Forward Model
Can you hear the shape of a room? Here is a matlab based simulator for exploring the problem, capable of simulating convex rooms with arbitrary numbers of microphones / speakers. The number of bounces is controllable, and occlusion and multiple reflections are automatically handled.
Matlab code: Room echo simulator
Grow! Ultra-fast Multiview Stereo:
Theoretical paper for transparent display using Coupled Total Internal Reflection / LCD panel :
Immersion Project, Make your laptop into a virtual-window through face-tracking + google streetview :
Designs for Directional Backlight:
Acoustic Landmine Detector (Senior Design Project, Tufts University):
Buried landmines can be hard to detect, especially if they have been buried for a long time. When vibrated. however, landmines interact dynamically with the soil around them. The detector works by transmitting two sound tones (two frequencies) and records the sound that bounces back. The detector analyzes the characteristic response of the landmine-dirt system and then determines whether a landmine is buried.
Two frequencies are transmitted into the ground. The detection algorithm detects the non-linear combination of these two frequencies. These non-linear (non-harmonic) peaks in the spectrum of the response is caused by the landmine bouncing against its environment.
Music Video: Youtube
PillowPal (HackMIT Finalist, 2012):
Ever had trouble waking up in the morning? Ever unconsciously turned off your own alarms? Never have this problem again with PillowPal! Your friends now have complete control over when you wake up. Isn’t that great? PillowPal allows your facebook friends to access your pillow online and turn on lights and music to wake you up in the morning. PillowPal is an attachment for your phone. It communicates with your phone through the audio port, so it works with almost every phone. The brains of the pillow are a picaxe microcontroller and a set of 32 RGB addressable LED’s which will blink different colors when its time to wake up. Work was done with Jesika Haria, Prabhav Jain, and Geza Kovacs.
There’s no app for that: Sudan sanctions are holding back innovation: