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Comment by ec109685 | Hacker News Reader

Is lidar still necessary if computer vision advances far enough? We drive just fine without radar.

At the current stage, depending on computer vision may be dangerous. See this BBC article about how it can be fooled [1]

[1] http://www.bbc.com/future/story/20170410-how-to-fool-artific...

Couple of issues with this point:

1) We don't just rely on our vision when driving but also on sound (nearby cars) and touch (feel of the road). I actually haven't seen any self driving car projects talk about this aspect which is interesting.

2) Self driving cars can't be just as good as humans they need to be effectively perfect. Quite a lot of people think they are amazing drivers i.e. infallible so mistakes from a self driving car aren't going to go down well.

There are deaf drivers, and I'd wager the vast majority of human drivers pay no attention to the feel of the road.

I haven't really seen many people talking about "Human sensor fusion" regarding sound/touch/etc, and I think it's a very important point.

Are driverless cars even measuring sound, vibration, and G-Forces? I'd like to better understand how those play into the whole sensor fusion of these systems.

You deserve some up-votes.

Tesla famously doesn't use LIDAR, saying cameras (possibly with parking radar) are good enough.

Here's a nice summary: https://cleantechnica.com/2016/07/29/tesla-google-disagree-l...

I'm not sure whether that isn't just a business decision. CMOS cameras are cheap, small, and they don't change very much. Ergo, once they manage to develop a solution using cameras, they won't have to retrofit the hardware in customers hands to support it, and they can still claim that oneday this car might drive itself.

With LIDAR, well, there's a new type of LIDAR coming out. Then there may be different successor designs and form factors.

Tesla has also killed people with this decision. They've had one fatal crash (at least) due to image based getting confused by a semi truck with a white cargo container in bright sunlight. It thought nothing was in that space and changed lanes accordingly; which the car ended up under the semi truck and the occupants crushed.

Active sensors are needed for human safety applications, passive doesn't make sense.

Tesla has saved people as well by being able to roll out this tech widely. Our eyes are passive and they work. Teslas do have radar sensors.

Sebastian Thrun will tell anyone who will listen that he is sorry he got the self-driving car world hooked on LIDAR. He is 100% behind computer vision now. He would much rather use several $10 web cameras than multi-hundred dollar LIDARs. If you look at term 1 of the Udacity self-driving car syllabus, it is CV and ML, zero about how to process point clouds.

NVIDIA is also betting on CV for self driving cars.

Human eyes have depth perception, a camera doesn't.

Does the human eye have anything special in that regard that couldn't be emulated by two side-by-side cameras? As far as i know, depth perception is mostly an awesome feature of our brain (software), not of our eyes (hardware).

The brain is also hardware, just extremely efficient. When compared to modern processors, the visual cortex does way more while using less energy.

The human eye has some interesting optical defects like chromatic aberration that man-made optical systems usually fix in hardware but that the brain fixes in software. These aberrations, when available to the software as uncorrected input, can provide information useful for determining how to focus properly (and by extension, focus distance, which gives you distance-to-point information dependent on DOF). [1]

Modern photographic lenses tend to contain a large number of lenses in series, a few of which often have an exotic property like being apochromatic, aspheric, or made of fluorite, but such well-corrected lenses may be counter-productive for machine vision. Phase detection in a DSLR relies on separate collection sites like stereo vision, but autofocus still hunts under bad conditions.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3189032/

Stereopsis and stereoblindness is actually a fascinating topic. Some humans don’t have it, and still manage to drive, ride bicycles, or fly planes.

The Mind's Eye by Oliver Sacks has an interesting chapter on a woman who managed to develop stereovision in her late 40s through vision therapy.

Humans have a huge amount of "common sense" knowledge that makes object recognition a lot easier, even without 3D information.

Even with only one eye, it has to focus differently for different distances. I think that information is somewhere present in the brain and can be used (even when not consciously accessible)

Some VR users (and IMAX 3D customers) have reported 'learning' stereovision.

I'm pretty sure I'm stereoblind. I think my brain is too lazy to combine images into 3D. Pot seemed to kick my brain into overdrive and process that signal. My friend laughs at me for "seeing in 3D for the first time" and doesn't believe me.

Binocular depth perception doesn't work past maybe 20-40ft, and safe one-eyed drivers exist. Other forms of depth perception could theoretically be done just as well with a camera as with an eye.

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