handle reading threaded frames from the Imagezmq

[mikahoy045]

Hi Jeff, I want to stream from camera to PC using imagezmq(camera stream to PC using normal open cv is okay). I plan to added custom yolov7 object detection. After digging the source it seems that yolov7 using loadstream function that runs the frames received using threads ( loadstream function line 266) that works basically like in here.

Is there any example codes or suggestion so that I can consume the imagezmq frame while keep the processing of the frame in threading (so that it still speeds up the fps even using CPU)?

[jeffbass]

I think you are asking about consuming the imageZMQ frames on the image receiving end (rather than threading the camera-image-sending end).

I use a receive frame loop in the main program with a thread to consume / process the frames in my imagehub repository.

The main program receiving frames in a forever loop is here.
The thread processing the frames is here at line 75. It is a simple process that writes the frames to disk, which is IO bound and makes if a good candidate for threading.

The frames are passed from the main image capture loop to the image thread using a deque from collections.deque. I use this because deque's are thread-safe. If you use some other way to pass frames from main to thread, you need to make sure your method is thread safe.

A thread to feed frames to a yolo7 consumer could work in the same way.