5 ms·

Just spit-balling, but could it be used for cheap depth perception, like a LIDAR alternative?

• Angostura 9y ago
  Sounds plausible to me.
• StavrosK 9y ago
  Probably, but so can two normal cameras, like the ones humans have in our heads.
  • KaiserPro 9y ago
    stereo cameras only give two viewpoints, it requires a lot of processing power to re-create the 3d scene. a lightfield gives you much more information making reconstruction much simpler. You can also see past occlusions, something not possible with stereo.
    • StavrosK 9y ago
      How can you see past occlusions?
      • PaulHoule 9y ago
        A stereo camera array can see past occlusions in the sense that some things are occluded to one camera but not to another. With a larger and more distributed camera array, cameras could be pointed everywhere so that every point in the field has a certain level of coverage.
        • StavrosK 9y ago
          The GP said you can see past occlusions with a Lytro and not with stereo, and that sounds exactly the other way around to me (as to you).
          • Jtsummers 9y ago
            You can do it with both, actually. Light field data allows you to simulate different viewing angles of the same scene. Depending on the sensor quality you can use this to "see around" objects which occlude the scene from a specific angle (like if you view the image from the center of the field of view). Some limitations, of course, similar to stereoscopic imagery. Using stereoscopic as an example, you can synthesize a 2d image with the center being between the two sensors. The further apart you place the sensors, up to some limit, the more you can "rotate" the scene. But you lose a lot of data when the viewing angles become too extreme. A light field image can be used for the same effect, but because it's one sensor your ability to rotate the scene will be constrained (as if you had two sensors very close together). Apparently the examples I saw years ago on Lytro's site aren't available anymore. It was a neat effect with their initial camera, I imagine higher quality cameras could do much more. A neat thing with light field sensors versus stereoscopic is that you have far more freedom in how you move around the scene. With two sensors you can only move "left and right" or "up and down". With light field data and one sensor you can move in any direction.
            • StavrosK 9y ago
              Ah, I see what you mean. You're constrained to viewpoints on the sensor, though, no? So usually a small square.
              • Jtsummers 9y ago
                Right. And with the initial cameras, which were neat but not breathtaking in their capabilities, you really only got a small ability to move around the scene. A larger sensor or a pair of these would offer greater capabilities for this application. I believe using an array of sensors was how their video camera worked, but I'm not 100%. (I spent a lot of time reading about light field stuffs back when Lytro was first announced, I was also tangentially connected to a synthetic aperture radar project so it piqued a lot of my curiosity at the time. I haven't kept up with the state-of-the-art since then, though.)
              • PaulHoule 9y ago
• matte_black 9y ago
  Do you really want “cheap” depth perception for a self driving car?
  • opencl 9y ago
    Yes? Why would you not want it to be cheap? Current self driving LIDAR units costing $75,000 seems like a pretty major barrier to mass producing the things.
  • Jtsummers 9y ago
    Perhaps read that as "inexpensive" rather than "cheap" if you take cheap to imply low quality. Light field sensors could greatly aid self-driving vehicles as a significant improvement over standard cameras and stereoscopic configurations for object detection. It's not as good as Lidar in some ways, but it's much less expensive and offers some of the same kinds of data (which means greater portability of algorithms or techniques between the two sensor types). And since cars need to see the same visual cues humans do, we need cameras anyways (for reading signs and road directions, lane detection, etc.) so using a light field sensor could offer a twofer. Improved object detection plus the ability to do visual detection we already need.