6 ms·

Do you think depth estimation could be done with two cameras plus computer vision (to find markers)? I think this is more or less what we do with our own eyes.

Do you think depth estimation could be done with two cameras plus computer vision (to find markers)? I think this is more or less what we do with our own eyes. Of course you would need much more processing power, but maybe for some applications the robot's brain doesn't need to be inside its body.

Mvandenbergh 6y ago
Parallax methods are widely used, I think it's how Tesla's driving assist features work. The problem with it is that humans don't just use binocular vision - we have a whole model of the world. So for instance, if I see an object, I usually know roughly how big it is supposed to be because I have a conception of "object". I also know that the straight line on both sides of an object is a wall, and that the wall continues behind the object and therefore the object is in front of the wall and the object is closer than the wall. That means I'm not just working with my binocular vision and it can be deceptive to think that because it works for human vision it will also work well for computer vision.
- treeman79 6y ago
  Lost binocular vision for a number of years back. You get around just fine without it. Got it back after some speciality glasses (PRISM). Was a complete shock see depth again. Didn’t seem to help anything getting it back. Mostly just trippy. Chairs were amazing to stare at.
  - etrautmann 6y ago
    I’m curious to hear more. What caused you to lose and then regain depth perception? Were you able to see with both eyes or did you lose vision in one eye temporarily?
    - arpa 6y ago
      If prism glasses helped regain depth perception, then probably something went wrong with eye motor function, causing diplopia (double image due to misalignment of eye). Could be trauma to the eye socket? Vision loss in one eye i think can be ruled out.
      - treeman79 6y ago
        Sixth cranial nerve issue. I can keep eyes aligned, but is extremely difficult and painful if cranial pressure is high. Reducing pressure resolves the issue. Both eyes are very healthy. At worse it’s +24 diapors, -1 power. When pressure is good it’s 0-2 diapors +3power. For awhile it was -6 diapors. At this point I have glasses for much of the range. Temple pain tells me when it’s time to switch glasses. Avoiding caffeine and other stimulants helps. Taking a Diamox will drop pressure in a couple of hours.
        tomcam 6y ago
        There is either a book or a great Joe Rogan podcast in your story. Thank you very much for sharing.
    - treeman79 6y ago
      Mix of minor strokes and high intercraniel pressure. My vision would switch from one eye to the other roughly every 30 seconds. Mostly seamlessly. Took ages to figure this out. Had some minor left brain issues. So writing would go gibberish every 30 seconds. Keeping a patch on right eye meant my vision went black every 30 seconds but my writing was fine when I could see. Left eye being patched meant writing mostly gibberish. Still had blackness every 30 seconds. Going on blood thinners resolved the vision going black and gibberish problems. Prism glasses fixed double vision problems. Medication for cranial pressure removes the need for prism glasses for about 10 hours. I have several extremely different pairs of glasses depending on what my brain is currently doing. Inhaled some caustic gas a few years ago. My blood went “sticky” from it. Apparently it activated a Latent blood disorder.
      - craftinator 6y ago
        This is the most interesting thing I've read today! Thank you for sharing!
        treeman79 6y ago
        Thanks! Took 3 years of hacking mind and body while mentally deficient to figure it all out. Leaned a lot from it all. Kind of forgot a lot too, but got most of it back now. Would take memory tests daily or more to see how “stupid” I was. Graphing my own cognitive decline and eventual resurgence was “interesting”
      - etrautmann 6y ago
        Whoa, I’m really sorry to hear that. Your story is fascinating and reminiscent of Michael Gazzaniga and others’ work with split brain patients.
  - cptnapalm 6y ago
    From a much shorter and very different route, once after an 18 hour straight Quake marathon, I looked around the my room and was startled at how everything looked. I was highly impressed by the graphics and depth perception.
    - treeman79 6y ago
      I took an art class a few years ago. Negative space drawing and perspective drawing will blow your mind after a 3 hour session. Walking outside you see lines and shadows everywhere. Entire perspective changes.
    - liability 6y ago
      This reminds me of the 'Tetris effect' in which people who play Tetris for prolonged periods of time will begin to experience Tetris-like hallucinations when they stop. I've experienced it myself and have trouble explaining it, but it's as though everything you see becomes Tetris-like in some way. You look at your dinner and see ways to rearrange the peas so they 'fit' with the mashed potatoes, or something like that. There's more to it than that though, there's a real sensation of things being moving blocks that must be fitted together. It's bizarre. But unlike Quake, Tetris isn't providing you with a 3D experience. That makes me wonder how much overlap there is between the two experiences.
- hnick 6y ago
  We can also go up and down abstraction levels at will. We can see a forest, then a tree, then a leaf. All different "objects", yet related. The ability to not distinguish each blade of grass in my yard and just see it all as "grass" is very useful for noticing and not stepping on what the dog left behind.
- bluGill 6y ago
  Note that the human system fails for things like the moon which look vastly different in size at different times. This is proof of your point.
michaelt 6y ago
The answer is 'sometimes' and it's known as stereo vision. Downsides include being less precise at longer distances (an object 1.5 meters away becomes a lot larger if it gets 1 meter closer, an object 150 meters away barely changes) and poor performance on surfaces with fewer features, or really dense features that all look alike (e.g. running across a field while spotting bumps and dips in the grass, or measuring whether sheets of steel are flat or not) In some cases this doesn't matter - a Roomba doesn't care if it's hard to see things 150 meters away, as rooms are rarely that big.

Mvandenbergh 6y ago

Parallax methods are widely used, I think it's how Tesla's driving assist features work. The problem with it is that humans don't just use binocular vision - we have a whole model of the world. So for instance, if I see an object, I usually know roughly how big it is supposed to be because I have a conception of "object". I also know that the straight line on both sides of an object is a wall, and that the wall continues behind the object and therefore the object is in front of the wall and the object is closer than the wall. That means I'm not just working with my binocular vision and it can be deceptive to think that because it works for human vision it will also work well for computer vision.

treeman79 6y ago
Lost binocular vision for a number of years back. You get around just fine without it. Got it back after some speciality glasses (PRISM). Was a complete shock see depth again. Didn’t seem to help anything getting it back. Mostly just trippy. Chairs were amazing to stare at.
- etrautmann 6y ago
  I’m curious to hear more. What caused you to lose and then regain depth perception? Were you able to see with both eyes or did you lose vision in one eye temporarily?
  - arpa 6y ago
    If prism glasses helped regain depth perception, then probably something went wrong with eye motor function, causing diplopia (double image due to misalignment of eye). Could be trauma to the eye socket? Vision loss in one eye i think can be ruled out.
    - treeman79 6y ago
      Sixth cranial nerve issue. I can keep eyes aligned, but is extremely difficult and painful if cranial pressure is high. Reducing pressure resolves the issue. Both eyes are very healthy. At worse it’s +24 diapors, -1 power. When pressure is good it’s 0-2 diapors +3power. For awhile it was -6 diapors. At this point I have glasses for much of the range. Temple pain tells me when it’s time to switch glasses. Avoiding caffeine and other stimulants helps. Taking a Diamox will drop pressure in a couple of hours.
      - tomcam 6y ago
        There is either a book or a great Joe Rogan podcast in your story. Thank you very much for sharing.
  - treeman79 6y ago
    Mix of minor strokes and high intercraniel pressure. My vision would switch from one eye to the other roughly every 30 seconds. Mostly seamlessly. Took ages to figure this out. Had some minor left brain issues. So writing would go gibberish every 30 seconds. Keeping a patch on right eye meant my vision went black every 30 seconds but my writing was fine when I could see. Left eye being patched meant writing mostly gibberish. Still had blackness every 30 seconds. Going on blood thinners resolved the vision going black and gibberish problems. Prism glasses fixed double vision problems. Medication for cranial pressure removes the need for prism glasses for about 10 hours. I have several extremely different pairs of glasses depending on what my brain is currently doing. Inhaled some caustic gas a few years ago. My blood went “sticky” from it. Apparently it activated a Latent blood disorder.
    - craftinator 6y ago
      This is the most interesting thing I've read today! Thank you for sharing!
      - treeman79 6y ago
        Thanks! Took 3 years of hacking mind and body while mentally deficient to figure it all out. Leaned a lot from it all. Kind of forgot a lot too, but got most of it back now. Would take memory tests daily or more to see how “stupid” I was. Graphing my own cognitive decline and eventual resurgence was “interesting”
    - etrautmann 6y ago
      Whoa, I’m really sorry to hear that. Your story is fascinating and reminiscent of Michael Gazzaniga and others’ work with split brain patients.
- cptnapalm 6y ago
  From a much shorter and very different route, once after an 18 hour straight Quake marathon, I looked around the my room and was startled at how everything looked. I was highly impressed by the graphics and depth perception.
  - treeman79 6y ago
    I took an art class a few years ago. Negative space drawing and perspective drawing will blow your mind after a 3 hour session. Walking outside you see lines and shadows everywhere. Entire perspective changes.
  - liability 6y ago
    This reminds me of the 'Tetris effect' in which people who play Tetris for prolonged periods of time will begin to experience Tetris-like hallucinations when they stop. I've experienced it myself and have trouble explaining it, but it's as though everything you see becomes Tetris-like in some way. You look at your dinner and see ways to rearrange the peas so they 'fit' with the mashed potatoes, or something like that. There's more to it than that though, there's a real sensation of things being moving blocks that must be fitted together. It's bizarre. But unlike Quake, Tetris isn't providing you with a 3D experience. That makes me wonder how much overlap there is between the two experiences.
hnick 6y ago
We can also go up and down abstraction levels at will. We can see a forest, then a tree, then a leaf. All different "objects", yet related. The ability to not distinguish each blade of grass in my yard and just see it all as "grass" is very useful for noticing and not stepping on what the dog left behind.
bluGill 6y ago
Note that the human system fails for things like the moon which look vastly different in size at different times. This is proof of your point.

michaelt 6y ago

The answer is 'sometimes' and it's known as stereo vision. Downsides include being less precise at longer distances (an object 1.5 meters away becomes a lot larger if it gets 1 meter closer, an object 150 meters away barely changes) and poor performance on surfaces with fewer features, or really dense features that all look alike (e.g. running across a field while spotting bumps and dips in the grass, or measuring whether sheets of steel are flat or not) In some cases this doesn't matter - a Roomba doesn't care if it's hard to see things 150 meters away, as rooms are rarely that big.