error: (-215:Assertion failed) !ssize.empty() in function 'resize' shows up when setting a-CodePudding

I was following a tutorial to build a facial recognition software:

small_frame = cv2.resize(frame, (0,0), fx=0.25,fy=0.25),
rgb_small_frame = small_frame[:,:,::-1]

when this error showed up:

cv2.error: OpenCV(4.6.0) /Users/xperience/actions-runner/_work/opencv-python/opencv-python/opencv/modules/imgproc/src/resize.cpp:4052: error: (-215:Assertion failed) !ssize.empty() in function 'resize'

CodePudding user response：

This problem was few times on Stackoverflow.

When cv2 can't get frame from file or webcam then it doesn't raise error but it return status False, and frame None and you should check one of this values before you run rest of code

ret, frame = cap.read()

if ret:  # if ret is True:
    small_frame = cv2.resize(frame, (0,0), fx=0.25,fy=0.25)
    # ... rest of code ...

ret, frame = cap.read()

if frame is not None:  # it can't be `if not frameret is True:`
    small_frame = cv2.resize(frame, (0,0), fx=0.25,fy=0.25)
    # ... rest of code ...