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Camera vs. Lidar

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Re: Camera vs. Lidar

#81

Post by hoseja »

rdtsc wrote: post #43
Complexicate wrote: post #18

Earlier quoted context omitted.

The human brain is horrible at building truly accurate 3D representations of the world. Our mental maps are constantly missing a magnitude of details while tricking us and creating approximations to fill in the blanks. Easy examples of this are optical illusions, ghosts, and ufos. There is also "selective attention tests" where a majority of people miss glaringly obvious events right in front of them, when they're fo…

But at the same time people don't think much about getting in their cars and driving to work or the grocery store. So it seems that a truly accurate 3D representations of the world are not necessary, at least for driving. Perhaps it's the resolution? Looking at the samples in the article, they are just terribly fuzzy, with a narrow field of view. If I had to drive and only see the world through that kind of view, I d…

People also crash all the time. I'd be OK with AI crashing even slightly less than humans. Rabid shock-media and various luddites aren't.

Re: Camera vs. Lidar

#82

Post by ebg13 »

semi-extrinsic wrote: post #74
ebg13 wrote: post #25

Earlier quoted context omitted.

You're not responding to what they said. The person you're responding to is talking about depth from stereo, not cognition. Lidar _also_ doesn't know what the glass feels like.

People who have good vision in one eye can usually get their drivers licence without problems. So the depth from stereo is not a necessary part of driving for humans.

It doesn't matter how you estimate depth, but you do have to estimate it to drive, and the first step before you can estimate is that your eyes (eye in your example) need to see pictures. Light entering the eye is an entirely different stage in the process than reasoning about said light.

Re: Camera vs. Lidar

#83

Post by anticristi »

noneckbeard wrote: post #62

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?!

I also feel that they make the 2D annotator's job very hard. I wore an eye patch yesterday (having fun with kids) and reality became extremely confusing. Our brain does not annotate on static 2D images. We annotate on stereoscopic video of moving objects.

Re: Camera vs. Lidar

#84

Post by KaiserPro »

cameldrv wrote: post #34

They are refuting a claim that wasn't made. If they need Lidar to do better annotations, fine. You'd only need the lidar on data collection/R&D cars though, and could just use cameras on production cars. The point Musk and others are making though is that the lidar on the market today has poor performance in weather. The cameras will struggle to a degree in weather as well, so not having good annotations when your de…

With respect, thats not what they are claiming

They are saying that lidar enhances the perception system to get more accurate dimensions and rotations of objects to a greater distance.

this means that you can predict far better, allowing you, for example, to drive at night full speed.

Weather affects visual systems as well. The "ooo rain kills lidar" is noise at best. Visual cameras are crap at night.

There is a reason that the radar augmented depth perception demo is in bright light, no rain. Because it almost certainly doesn't work as well at night, and will probably need a separate model.

Re: Camera vs. Lidar

#85

Post by sidcool »

Regardless of which side of the 'Efficacy of Lidar' argument one is, it's impressive how much impact Elon Musk's statement has on the industry.

Re: Camera vs. Lidar

#86

Post by KaiserPro »

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…

Yes, we can. We can do it with one eye too.

but it takes at least 10 years to train.

But most of the time we are not building a 3d map from points. we are building it from object inference.

There are many advantages that we have over machines:

o The eye seens much beter in the dark o It has a massive dynamic range, allowing us to see both light and dark things o it moves to where the threat is o if it's occluded it can move to get a better image o it has a massive database of objects in context o each object has a mass, dimension, speed and location it should be seen in

None of those are 3d maps, they are all inference, where one can derrive the threat/advantage based on history.

We can't make machines do that yet.

you are correct that two cameras allows for better 3d pointcloud making in some situations. but a moving single camera is better than a static multiview camera.

however even then the 3d map isn't all that great, and has a massive latency compared to lidar.

Re: Camera vs. Lidar

#87

Post by imtringued »

jholman wrote: post #68
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…

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…

Two eyes have a bigger field of view.

https://petmusicacademy.files.wordpress.com/2017/04/vision.j...

Re: Camera vs. Lidar

#88

Post by jamesrom »

>If your perception system is weak or inaccurate, your ability to forecast the future will be dramatically reduced.

This is reasoning is exactly backwards. If your perception system can forecast accurately, it simply must not be weak or inaccurate.

The question here is, what is important information for a system to perceive to make accurate forecasts? Lidar might help a bit... But we know it simply is not required.

Re: Camera vs. Lidar

#89

Post by airnomad »

What if we have sensors/cameras/etc along the road and they feed data to whichever car is there?

And if we also have cars share their sensor data?

Would that speed things up in terms of achieving full autonomy?

Re: Camera vs. Lidar

#90

Post by hrghfdbdsbg »

Symmetry wrote: post #76
donkeyd wrote: post #73

Earlier quoted context omitted.

> taking consecutive frames (2D images) we can estimate per pixel depth Yeah, I find it odd that they're bringing up Elon's statement about LiDAR, but then completely ignore that they spoke about creating 3D models based on video. They even showed [0] how good of a 3d model they could create based on dat from their cameras. So they could just as well annotate in 3D. 0: https://youtu.be/Ucp0TTmvqOE?t=8217

Egomotion is very useful but relies on being able to reliably extract features from objects which isn't always possible. Smooth, monochromatic walls do exist and it's imperative a car be able to avoid them. It is possible for a human to figure out (almost always) their shape and distance form visual cues but our brains are throwing far more computational horsepower at the task than even Tesla's new computer has avail…

"Smooth, monochromatic walls do exist and it's imperative a car be able to avoid them."

Aren't those the types of walls, barriers, truck behinds that tesla's keep ramming into? :S

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