Hello! I have a quick question about some performance issues that my team has ben experiencing when using an OAK-D W camera with a Raspberry Pi 4.

We have the camera connected to one of the USB3 ports on the Pi, and when we run the system, we have found that our disparity image quality is quite poor - we get a serious amount of noise and large clusters of spurious points that are being registered "close" to the camera (in the disparity image).

However, when we run the demo program with either the low bandwidth option "-bandw low" or the usb 2 manual select -usbs usb2 (which defaults to low bandwidth mode I think), the image is much closer to what we expect to recieve.

When we run the camera in the exact same way on our laptop, we do not see any issues.

Here you can see the difference between a "good" image (raspi 4 with low bandwidth mode)

and "bad" image (raspi 4):

We suspect that the issue is related to power, so we have used an external powered hub to power the camera, but we see the same behaviour.

Do you have any ideas? Any help would be appreciated!

  • erik replied to this.

    Hi petey ,
    If you look closely (top of the cv2 window), you can see that one is colorized disparity (it usually looks nicer), and the other is colorized depth (doesn't look as good). So the depth accuracy is exactly the same, but for some reason, it appears that depthai_demo shows depth instead of disparity when usb3, and disparity on usb2. We will investigate this further.
    Thanks, Erik