Pynq webcam problem

Hi, i am a beginner of using ultra96 v2 board with sd card image pynq ultra96 v2 v2.4.
I just successfully download the repo of computervision.
When i running

I do not why the fps of running HW filter2D + dilate on input frames from USB camera in real-time is only 4~5 fps.
I have tried to only read the frame without doing filtering and the fps is also only 5 fps.
Could someone teach me why this happened?
Besides, the fps I tried on my own computer without ultra96 board is about 30 fps.
But when the environment changes to ultra96 v2 pynq , fps becomes only 5.
Thanks a lot!!!

That 5 fps is the pure software performance. imshow is trying to display that on your screen. So the performance bottleneck is this software video data path where you fetch data from camera and display on your screen. When you run HW filter2D, performance does not drop much; it means your software video data path is dominating the overall performance. There are a couple of ideas to improve this which I think you can find online.