OpenCV Error: (-215)size.width>0 && size.height>0 in function imshow

Question

I am trying to make a face tracker that combines Haar Cascade Classification with Lucas Kanade good feature detection. However, I keep getting an error that I cannot figure

Answer 1

I also met the error message in raspberry pi 3, but my solution is reload kernel of camera after search on google, hope it can help you.

sudo modprobe bcm2835-v4l2

BTW, for this error please check your camera and file path is workable or not