OpenCV Error: Assertion failed (size.width>0 && size.height>0) in imshow

Question

I am running the following code on Raspberry Pi with pi camera, I have the broadcom drivers for it and all, but I am getting an error. Perhaps something to do with the dimen

Answer 1

Provide an id to VideoCapture.

cap = cv2.VideoCapture(0)

Also check the value of ret, see if it's TRUE or FALSE

print (ret)

Edit:

To capture a video, you need to create a VideoCapture object. Its argument can be either the device index or the name of a video file. Device index is just the number to specify which camera.

cap = cv2.VideoCapture(0)

To check whether the cap has been initialized or not, you can use cap.isOpened() function, which returns True for successful initialization and False for failure.

if cap.isOpened() == False:
    print ("VideoCapture failed")

cap.read() returns a bool (True/False). If frame is read correctly, it will be True. So you can check end of the video by checking this return value.

ret, frame = cap.read()
if ret == False:
    print("Frame is empty")

Further reading here.