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Camera vs. Lidar

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Re: Camera vs. Lidar

#61

Post by kajecounterhack »

ebg13 wrote: post #23
sairahul82 wrote: post #17

Earlier quoted context omitted.

The first thing we need to remember is the self driving doesn't work like our brain. If they do then we don't need to train them with billions of images. So the main problem is not just building the 3d models. For example we don't crash into the car because we never seen that car model or that kind of vehicle before. Check https://cdn.technologyreview.com/i/images/bikeedgecasepredic... we never think that there is a…

> So the main problem is not just building the 3d models That's not relevant when discussing which technology to use to build the 3d models. Everything you said is accurate until the last few sentences. Lidar provide the same information (line of sight depth) as stereo cameras, just in a different way. The person you're responding to is talking about depth from stereo, not cognition.

> Lidar provide the same information (line of sight depth) as stereo cameras, just in a different way.

This is incorrect, the amount of parallax you need to get the same kind of accurate depth using camera is infeasible. Velodynes other common lidar now gets you points accurate at 150m+. Cameras can't do that, and if you use nets to guess you'll still make mistakes.

> The person you're responding to is talking about depth from stereo, not cognition.

You miss the point; saying human 3D reconstruction works because of sensors without world context is naive. The response was trying to capture that; human perception systems utilize context / background knowledge extensively.

Re: Camera vs. Lidar

#62

Post by noneckbeard »

Some of this feels very cherry-picked. They’re comparing lidar vs camera on snapshots, when a model will always be continuously built as the scene changes.

There’s also one instance where it gives lidar the advantage because it’s mounted on top of the car and can see over signs. What?!

Re: Camera vs. Lidar

#63

Post by nradov »

alkonaut wrote: post #59
worik wrote: post #53

This is ignoring the Elephant in the room: The AI is not good enough often enough for general purpose AVs. In restricted settings it will be great (container terminals, warehouses...) but from every thing I have seen, from the outside as I am not a insider, the last little bit of safety seems unobtainable with neural networks. I so want to be wrong, and please tell me why I am. I want my next care to have a cocktail…

Cars will reach 50% and 75% and 95% autonomy but they won’t reach 100% unless we change infra to be controlled. So long as they are driving among humans on roads made for humans they will never be 100% autonomous. 100% autonomy might sound like just a little more than 95% but it’s not. At 100 is where a car can be built to not have a driver. Its passengers can be drunk or not know how to drive. It’s a huge difference…

How do you expect human remote control to work reliably enough for safety critical situations when our existing cellular data network fails so frequently? What happens when a construction crew accidentally cuts through the backhaul fiber?

Re: Camera vs. Lidar

#64

Post by alkonaut »

nradov wrote: post #63
alkonaut wrote: post #59

Earlier quoted context omitted.

Cars will reach 50% and 75% and 95% autonomy but they won’t reach 100% unless we change infra to be controlled. So long as they are driving among humans on roads made for humans they will never be 100% autonomous. 100% autonomy might sound like just a little more than 95% but it’s not. At 100 is where a car can be built to not have a driver. Its passengers can be drunk or not know how to drive. It’s a huge difference…

How do you expect human remote control to work reliably enough for safety critical situations when our existing cellular data network fails so frequently? What happens when a construction crew accidentally cuts through the backhaul fiber?

The handover will be after the car stops because it’s confused. If there is no cell network or no operator available the car is simply stranded on the side of the road, just as after a mechanical failure. Operators can’t help “unknown situations” while moving.

Re: Camera vs. Lidar

#65

Post by josephagoss »

pfundstein wrote: post #36
mantap wrote: post #32

Earlier quoted context omitted.

You cannot have false negatives. Ever. You cannot have a situation where the system doesn't see a pedestrian and runs over them at without noticing. So you need to make a very convincing argument that it can't happen. With cameras and computer vision there's no way to prove it. There is always a chance that it will glitch out for a second and kill someone.

Autonomous vehicles don't need to be perfect drivers -- from it, they just need to be better than humans.

A million people die per year due to road deaths, about 40,000 of those in the USA.

If what you say is true then a future where robot cars kill 500,000 per year and 20,000 in the USA would be considered acceptable.

Yet we know this is absolutely not the case, no society will ever stand for such a massive death toll due to robot usage. Are there any industries today where robots are allowed to kill so many?

We accept deaths because of human failing as there is no other way, the alternative is no cars.

So for us to hand over the reins to robots they need to be near perfect, think the accident rates of the airline industry as the only acceptable goal.

Re: Camera vs. Lidar

#66

Post by DannyBee »

aidenn0 wrote: post #27

This completely fails to address Musk's argument: that for a L5 car you need to be able to drive in inclement weather where LIDAR does not work reliably. Musk may be right or wrong, but this article is a non-sequitur.

Musk has made a lot of arguments over the years. His argument was that lidar is a crutch because people do it without lidar.

Except people don't drive reliably in inclement weather at all, so you don't really want that as the gold standard.

Training a car to be as good as average people driving in the rain/snow would be horrible.

Re: Camera vs. Lidar

#67

Post by joshvm »

tgog wrote: post #3

This completely neglects the fact that humans can build near perfect 3D representations of the world with 2D images stitched together with the parallax neural nets in our brain. This blogpost briefly mentions it in one line as a throwaway and says you'd need extremely high resolution cameras?? Doesn't make sense at all. Two cameras of any resolution spaced a regular distance apart should be able to build a better par…

Others have commented about the human aspect.

> Two cameras of any resolution spaced a regular distance apart should be able to build a better parallax 3D model than any one camera alone.

This is true if the platform isn't moving.

If you have the time dimension and you have good knowledge of motion between frames (difficult), you can use the two views as a virtual stereo pair. This is called monocular visual/inertial-SLAM. You can supplement with GPS, 2D lidar, odometry and IMU to probabalistically fuse everything together. There have been some nice results published over the years.

But in general yes, you'll always be better off if you have a proper stereo pair with a camera either side of the car.

Re: Camera vs. Lidar

#68

Post by jholman »

mbrumlow wrote: post #7
jsharf wrote: post #4

Earlier quoted context omitted.

I think most of our ability to judge relative distance is based on our brains judgement of lighting, texture, inference, and sound. While having two eyes helps a lot, you can still navigate a complex office environment with one eye closed. It just takes a bit more care.

When I was younger I remember hearing about how we can do all these things because we have 2 eyes. And that depth perception is what gives us the ability to not walk into walls, and do other things including driving. I have thought about this many times and often wondered why when closing one eye I am still able to function. Sense then I have thought strongly that having depth perception is used for training some oth…

Take one class on perception, read one textbook, you'll immediately find that stereo perception isn't very important. Your brain uses a host of depth queues, and stereo vision is just one of them.

Some of them translate trivially to photos/TV/etc, like convergent lines or texture gradient. Some of them are surprisingly physical, like feedback from your eyes about vergence or focal distance.

Stereo is highly effective up close, say within 10 meters (yards). And it works faster than many modes. It's absolutely fantastic for catching things out of the air. Given our intraocular distance, it's basically garbage past, I dunno, 30m or something? (obviously it degrades smoothly across distance)

I've heard more than one academic (evolutionary cognitive psychologists, etc) speculate that the single biggest evolutionary advantage of having two eyes is to have a spare in the event of damage. That might well be just whimsy and exaggeration, but I think it puts a helpful alternate perspective on it (pun!).

Re: Camera vs. Lidar

#69

Post by rkangel »

sairahul82 wrote: post #17
tgog wrote: post #3

This completely neglects the fact that humans can build near perfect 3D representations of the world with 2D images stitched together with the parallax neural nets in our brain. This blogpost briefly mentions it in one line as a throwaway and says you'd need extremely high resolution cameras?? Doesn't make sense at all. Two cameras of any resolution spaced a regular distance apart should be able to build a better par…

The first thing we need to remember is the self driving doesn't work like our brain. If they do then we don't need to train them with billions of images. So the main problem is not just building the 3d models. For example we don't crash into the car because we never seen that car model or that kind of vehicle before. Check https://cdn.technologyreview.com/i/images/bikeedgecasepredic... we never think that there is a…

> The first thing we need to remember is the self driving doesn't work like our brain. If they do then we don't need to train them with billions of images.

I had always assumed that the first few years of infancy was effectively a period of training a neural net (the brain) against a continuous series of images (everything seen).

Re: Camera vs. Lidar

#70

Post by jholman »

pazimzadeh wrote: post #55
mbrumlow wrote: post #7

Earlier quoted context omitted.

When I was younger I remember hearing about how we can do all these things because we have 2 eyes. And that depth perception is what gives us the ability to not walk into walls, and do other things including driving. I have thought about this many times and often wondered why when closing one eye I am still able to function. Sense then I have thought strongly that having depth perception is used for training some oth…

I'm skeptical of the claim that a major reason for having two eyes is depth perception. One reason why you're still able to function is that you don't rely on your sense of depth that much these days. i.e. You don't need to gage where a spear or arrow will land. Even in a car, you are effectively on a one dimensional track and only have to decided to go left or right. If you only had one eye, then in situations where…

See my sibling comment: with respect to stereo vision, its greatest strength is nearby fast-moving things, great for stuff like dodging or catching or punching.

If you wanna launch spears or arrows, depth perception is incredibly important, but stereo vision will not help. Not with this intraocular distance, anyway.

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