OAK-D-PRO - IR flood illuminator & exposure?

dexter

I just started using this device and activated the floodlight by setting the intensity (dot off).
I'm logging exposure time and sensitivity of mono frames and especially sensitivity changes based on IR intensity. I'm thinking it's the auto exposure that makes the image look very much the same over different intensities.
I'm running at 20 fps and the exposure time is 30 ms most of the time, sometimes 20. Sensitivity changes more.
I'm using this for facial networks so the face is closer to the camera than the surroundings and thus looks a bit whitewashed. I tried setting the auto exposure region to where the face is, but that didn't seem to make any difference. Are there more settings that can interact with exposure region?

jakaskerl

Hi @dexter
Could you provide any demo for this and the code you are using? I tested it locally and had no problems with it.

Thanks,
Jaka

dexter

jakaskerl

It's a bit complicated to reduce my setup so something small, I was just trying to figure out if what I see is expected. I just did a test when I set the region to a part of the image that is very dark and it did change the exposure quite a bit so it looks like it's working. This means that the face probably should be pretty whitish then since it always goes for about the same result independent of IR intensity. It's normal that exposure time is either 20 or 30 ms and it's mostly sensitivity that's changing?
Is there a good way to control IR intensity dynamically based on e.g. the sensitivity value that's fed back?

jakaskerl

Hi @dexter
20-30ms is a long exposure time, but I assume you are testing this in the dark.

dexter Is there a good way to control IR intensity dynamically based on e.g. the sensitivity value that's fed back?

There was AUTO IR on SDK: https://docs-old.luxonis.com/projects/sdk/en/latest/features/auto_ir/#usage, but it's not available on API at the moment.

Thanks,
Jaka

dexter

Thanks jakaskerl

I read about that before, but I couldn't find it in C++. I would also like some limits for the automatic control since I want it on even when it's bright to assure penetrating e.g. sunglasses.

For now I use IR intensity 0.3, turn off anti banding, set the exposure limit to 10000, activate auto exposure and "continuously" update the exposure region.

With that I get an exposure time of 10 ms (what I set) and a sensitivity around 235 for a face about 0.7 meters away and a darkish room sitting in front of a fairly bright monitor.

The sensitive changes when changing the distance between face and camera, so it appears to work ok. I'll have to see what happens when I take it outside and sun light…