rzw2

An interesting project to design and develop a 3D structured light camera around a nvidia jetson, camera and projector.

What part did you design? I used an IMX8, and had issues with the CSI-MIPI RX, the fifo kept overflowing and crashing the AXI bridge, which could only be fixed by rebooting the SoC, such a pain!

A quick article comparing the intel realsense D435 which uses active stereo to measure depth vs a iToF camera made by my startup Chronoptics.

Maybe Intel is developing a new chip architecture and want to support linux from day 0? Or does Intel want a team of Kernel developers for their AI Silicon play, support the lower level architecture, or for their GPU play?

ST is adding to it's depth sensor portfolio, added iToF image sensors, which compliments it's single point dToF sensors.

Got to take credit after it is successful, but if it was a flop blame the external agency.

A tutorial introduction to the direct Time-of-Flight (dToF) signal chain and typical artifacts introduced due to detector and processing electronic limitations.

Short of a dot-com burst I don't see a glut of software engineers. However, as the career prospects are better known there are more people thinking they want to be a software developer, will this increase the talent pool and decrease demand?

There are plenty of other 3D depth cameras out there, just not with the brand recognition of Intel, and now the quick and easy purchase of one unit at $200USD.

Makes sense, if you have a product where you can make a profit on the manufacturing, why would you stop supply. Intel never broke out Realsense in any public finical data, I wonder if the R&D was not profitable, and is not a core part of Intel's business so the new CEO decided to shut it down.

Shameless self promotion, I'm a co-founder of Chronoptics and we design bespoke iToF depth cameras, have been thinking we should release a module to fill up the gap in the market caused by Intel's move.

Analog devices on the system design of a time-of-flight depth camera, as Analog Devices is building on the core Microsoft ToF pixel technology.

Looks like google is jumping on designing their own silicon, like Apple.

The different components that go into designing a 3D time-of-flight depth camera.

Maybe, would be very interesting to investigate.

Thanks, got any references to how the surveying equipment de-aliasing method worked?

Im guessing like Sony, it's hard to support such chips because of the underlying complexities. Melexis has open datasheets and can purchase individual sensors off mouser.

At those resolutions and frame rates multiview stereo is probably your best technology for the moment.

The microsoft kinect does 3 frequency measurements to get the higher distance precision of higher modulation frequencies and to extend the maximum distance so the phase wrapping (aliasing) can be solved.

Based on some Microsoft patent filings and other research papers I wrote a short article on possible phase unwrapping methods on iToF sensors, https://medium.com/chronoptics-time-of-flight/phase-wrapping...

Microsoft licensed their sensor to Analog devices, and you can buy the mega-pixel iToF sensor and build a iToF camera. https://www.analog.com/en/products/ADSD3100.html?icid=ToF-ad...

Or build a camera with multiple sensors capturing different FoVs.

Samsung have published papers on a 1.2MegaPixel ToF sensors, but currently only have a VGA sensor available. https://ieeexplore.ieee.org/abstract/document/9365854 https://www.samsung.com/semiconductor/minisite/isocell/visio...

There are three different methods. 1) TDMA (Time division multiplexing). Some sync system so only one camera is emitting light at a given time. The Microsoft Azure Kinect uses this with the 3.5mm sync cable, this enables up to 3 cameras to illuminate at different times.

2) Frequency domain. iToF cameras use different modulation frequencies, you can set different modulation frequencies and the signals won't interfere. The other cameras photon's will contribute to photon shot noise. Or randomly change modulation frequencies by a small amount during the integration time, which is supported by some sensors.

3) Randomly change timing during integration time, this is more common with pulsed ToF cameras. Analog devices had an example of this in their booth at CES in 2020.

There are two issues with sunlight and iToF. The sunlight photons saturate the pixel, and you get no useful measurement. The dominant noise source of iToF is photon shot noise [1], so sunlight photons contribute heavily to noise. Increase your laser power, use better optical notch filters, decrease the sensor integration time, and do more image filtering. I'm a cofounder at Chronoptics and we've developed a sunlight capable ToF camera, https://youtu.be/7vMI37S0w3Q

[1] https://en.wikipedia.org/wiki/Shot_noise

There has been some work on resolving multipath errors with indirect ToF, Chronoptics (I'm a cofounder) recently licensed our technology to Melexis in automotive.

Here's a blog post I wrote about resolving multipath https://medium.com/chronoptics-time-of-flight/multipath-inte...

And a link to the announcement from Melexis https://www.melexis.com/en/news/2021/4mar2021-melexis-announ...