How the Reference Intensity Is Chosen After and Event Detection and On Start Up

Hello everyone,

I recently had some questions regarding the nature of the reference intensity for event detections, specifically how the reference intensity is chosen following an event detection and how it is chosen after a camera is started. I couldn't find any information regarding this in the documentation so I reached out to Prophesee support, who got back to me with a response. I figured I would share their answer here in case anyone else comes looking for this information.

---- on Tue, 29 Jul 2025 04:03:25 "Prophesee Support Team" wrote ----

Hello,

The new reference value is the one that the pixel sees at the end of refractory period.

At the power-up of the sensor the pixel are allowed to send events only after they're settled : the transient setting-up of the photocurrent for all the pixels of the array should theoretically trigger events , but the circuit actualy ignore them and no events are generated.

Let me know if it's clear.

Best Regards, Artiom for Prophesee Support Team

To get the best support, stay up to date with Prophesee's latest software release. Metavision SDK 5.1 is now available!

---- on Fri, 25 Jul 2025 22:54:48 +0200 wrote ----

Greetings,

I have a question regarding the function of the event cameras (particularly the IMX636 sensor). After an event is detected, the pixel that made the detection is blind for the refractory period, after which it becomes able to detect again. When this happens, how is the new reference intensity chosen? Is it based on the intensity that triggered the event, or is it chosen based somehow on the intensity that the pixel sees after the refractory period? I have not been able to find any clarification for this in the documentation.

On a related note, how is the reference intensity chosen when the event camera is first turned on?

I appreciate your help.