Noisy image from OAK-D Pro W

rbn23

When I record left and right rectified images, my right image is very noisy. Here is an example:

Left

Right

I followed the samples for camera settings:

controlIn.out.link(monoLeft.inputControl)
controlIn.out.link(monoRight.inputControl)
controlQueue = device.getInputQueue(controlIn.getStreamName())
ctrl = dai.CameraControl()
ctrl.setAutoExposureEnable()
ctrl.setAutoExposureLimit(10000)
controlQueue.send(ctrl)

Did I miss something?

jakaskerl

Hi @rbn23
How are you recording the left and right streams? Are images for left and right mono cameras not noisy?

Thanks,
Jaka

rbn23

I take each frame as opencv image from the queue and save it with cv::imwrite()

I have a second OAK-D-Pro W camera and with this one (same code) the images are not noisy. To verify if unrectified image is not noisy I need to take a test with strong sunlight, since the problem with the noisy image only happes in very bright scenes.

jakaskerl

rbn23
Does this happen when only using one camera (left or right) at one time? Seems strange to me that sensor exposure would cause this on one device but not on the other.

Generally the left camera drives the right so setting both to different settings would cause issues. Perhaps only set the master camera's control.

Thanks,
Jaka

rbn23

jakaskerl

I am using dai.node.StereoDepth node. The quality of the depth image was very bad what made me wonder. When I looked at the rectified images I saw that the right one was noisy.

I followed the depthai examples that set coltrols for the mono cameras the following way:

controlIn.out.link(monoLeft.inputControl)
controlIn.out.link(monoRight.inputControl)

Is this wrong for unsing stereo node? When Left camera sets the right settings, why send the control also to the right camera?

This still wouldn't explain why it only happens with one OAK module. I have 3 OAK-D Pro W and only one has this problem. The others look fine even in full sunlight, all running with the same code. Maybe the image sensor is somehow broken?

jakaskerl

rbn23
The connection board-sensor might be a bit worse which could cause issues when setting very low exposure time. Is the unrectified image noisy as well?
I'm trying to figure out if this is a sensor fault or perhaps calibration or some other component.

Thanks,
Jaka

rbn23

Right now it's cloudy outside, so I cannot test and check the unrectified images. I will test when I get full sunlight again

jakaskerl

rbn23 Can you shine a bright light perhaps?

rbn23

I set the camera right underneath the ceiling lights and got these results with manual exposure of 100us and iso 100:

left

right

right image is noisy again

jakaskerl

rbn23
Ok, good, thanks.

cc @Luxonis-Alex

rbn23

Is there any update from your side?

Luxonis-Alex

@rbn23 I can't seem to replicate this noise on just one of the sensors. A couple things to check:

is a recent depthai release in use (e.g. 2.28.0.0), at some point we improved the sensor configs
might be temperature related, could you check with the device cooled down, does this issue appear right away after power on, or after running for some time. Try also a simple pipeline (no NN, no VideoEncoder, ...)
the hardware revision of the device, so we can recheck with the same version you have. Best if you could get the output of depthai-python/examples/calibration/calibration_dump.py