Device side processing

jonaskh

Hello,

I have a static OAK-1 POE camera that is detecting objects that will move on a conveyor belt across the frames.

For each frame I would like to retrieve detections, and then only as the object is leaving the frame do I send data to the host about which detections that one object has.

I am able to implement this on host side by tracking variables across frames, however I would like to implement this on the device instead, so that data is transferred to host only once when the object leaves the frame, and then reset when a new object enters.

I have looked into both the script node and callback functions, but am unsure of how to keep track of the previous frame data on the device. I would also like to not use the SDK if possible.

In essence, I would like to know if it is possible to store detections from a previous frame on the device, and then

update/access this information with the next frame detections without going through host.

Any pointers as to how this is achieved is appreciated 🙂

Thank you

jakaskerl

Hi jonaskh
You can use the script node to achieve that. You can access the frame/detection inside the script by calling node.io['name of input'].get(). Then you can store it inside a dict or a list.
You can also use the ImgFrame.getTimestamp() and ImgFrame.getSequenceNum() functions for synchronization on the device side to make sure you are correctly accessing and deleting frames and NN results.

Thanks,
Jaka