I noticed recently that my DAVIS 240C produces excessive amounts of positively signed events if I stimulate it with slow movements, whereas if I stimulate it with fast motions it produces predominantly negative signed events. I have tested this by summing up the net polarities of all the events produced. My camera has a couple of "dead" pixels which constantly produce positive events, but those have been taken into account. Interestingly, a colleague who is working with the same camera has reported the exact same issue.
What I was wondering was if anyone knew of or could recommend a particular setting or paramter in the BiasGen that we could play around with to solve this particular problem.
Many thanks!
Timo
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sorry for my late reply (I was on hoidays). The amount of positive vs negative events can be easily controlled by changing the ON (OnBn) and OFF (OffBn) thresholds. Have a look at our bias setting user guide, at this link: https://inilabs.com/support/hardware/biasing/
yes the pixel biases are acting on the transistors of the pixel circuits.
To have a better understanding please have a look at this paper: http://ieeexplore.ieee.org/abstract/document/4444573/
The names are also preserved On, Off , Threshold etc..
is this what you were asking for?
Last edit: Federico Corradi 2017-08-29
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi all!
I noticed recently that my DAVIS 240C produces excessive amounts of positively signed events if I stimulate it with slow movements, whereas if I stimulate it with fast motions it produces predominantly negative signed events. I have tested this by summing up the net polarities of all the events produced. My camera has a couple of "dead" pixels which constantly produce positive events, but those have been taken into account. Interestingly, a colleague who is working with the same camera has reported the exact same issue.
What I was wondering was if anyone knew of or could recommend a particular setting or paramter in the BiasGen that we could play around with to solve this particular problem.
Many thanks!
Timo
Hi Timo,
sorry for my late reply (I was on hoidays). The amount of positive vs negative events can be easily controlled by changing the ON (OnBn) and OFF (OffBn) thresholds. Have a look at our bias setting user guide, at this link: https://inilabs.com/support/hardware/biasing/
In addition, if you want to observe fast movements I suggest you use the bias settings that you can find here: https://github.com/SensorsINI/jaer/blob/master/biasgenSettings/Davis240bc/C-fast.xml
Let me know if the user guide and my suggestion will solve your issue.
with best regards,
Federico
Hi Federico,
Yeah, that has solved it, thank you! I'm trying to work out what this slider actually changes on the camera, can you help me out with this at all?
Hi Timo,
yes the pixel biases are acting on the transistors of the pixel circuits.
To have a better understanding please have a look at this paper: http://ieeexplore.ieee.org/abstract/document/4444573/
The names are also preserved On, Off , Threshold etc..
is this what you were asking for?
Last edit: Federico Corradi 2017-08-29