Hacker News Reader

Comment by onion2k | Hacker News Reader

This could be really useful for finding birds in trees when I'm out with my camera...

Would work! One of the first applications I made was a processing layer returning, in spherical coordinates centered at an arbitrary reference point, what the system determined as the "primary sound source".

In demo, the two angles drove a pair of servos steering a laser pointer. Followed the loudest object around the room :)

IME, finding a way to communicate the information to the user is often non-intuitive. That is to say, once a device has located birds in trees, how would you like it to inform you?

My first thought is for something like an arrow visible through the viewfinder, a bit like a damage indicator in an FPS game like Halo.

Hm. Doable. I think the hard part for that then might be getting the real time information about the position and orientation of the viewfinder in high enough resolution.

Keep in mind "the black box" can output the position in 3 space (x,y,z, measured in mm) of coherent sound sources, but to know where those are relative to the camera, so that once can draw a little arrow, can be hard.

I'd like to try hooking it up to a VR/AR headset, since I imagine those already handle the task of knowing precisely where my head is and where it's looking.

I think this might be possible with a phone that has AR support - you'd scan a QR code on the sound camera to capture its position relative to the world, then the phone could display a 3D view through the camera of where the sound source(s) are.

Oh that's interesting! Is your thinking something like:

1. mount the array on a tripod somewhere in the frame of the camera 2. the array is covered with an assortment of fiducials, 3. software uses the known intrinsics and extrinsics of the camera to figure out the array position relative to the camera 4. do the obvious thing with chaining transforms until you get the sound source position relative to the camera

If so, I think that would work, but would be a lot of coding to do all that CV...

> phone that has AR support

I take it cell phones now do much of this work?

Reply on news.ycombinator.com