Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

Fantastic! This fascinates me how you have reversed engineered a cheap camera to make it fit for purpose and shared your work. It could have applications in low budget computer vision projects. I am researching global shutter cameras now. Thinking Sony IMX264. Quite expensive in a enclosure from Flir or Lucid. Do you know what sort of FPS you could record? Dynamic range? QE etc.


Thank you! That's super cool :) The fastest strobe we used was a 500ns strobe, which is a 1/(2e6)th of a second exposure. The Pi cameras use the OmniVision OV5647, dynamic range of 67 dB @ 8x gain.

I'm pretty curious as to what you've discovered / worked on so far or have any interesting CV ideas you'd like to see?


do you know how many bits of depth the raw frames for Pi Camera V1 and V2 have?

Do we know the "gamma" curves, i.e. numerical intensity value as a function of light collected proportional to the number of photons?

67dB = 6.7B => brightest over softest intensity = 10^6.7 = 5 000 000

thats ln(10^6.7)/ln(2) = 22.257 bits, that's unheard of for camera sensors I have looked up, so I assume the reported values are "gamma" compressed before digitization.

Would you have interest in characterizing or collaborating on characterizing the exact compression function for the V1 and V2? Relevant literature seems to be Steve Mann's comparametric equations: https://en.wikipedia.org/wiki/Comparametric_equation

(I am interested in high dynamic range, and high monochromatic or color bit depth for an experiment, which will progress much faster if I can start out with a higher dynamic range and bit depth sensor, I will need to oversample to observe a phenomenon, and every bit of increased depth a sensor has compared with another sensor would mean the experiments can be run 4 times as fast...)


I am very new to the space.

I'd probably like to have a go at replicating some of the Blue River, Bilbery ideas but on a budget. That is sensing weeds or crop issues on the move therefore requiring global shutter. Uniform light throughout the day/night is another issue I am thinking through.

Working through fastai when I get a chance but my biggest issue is finding domain specific datasets.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: