Check return value in python tutorial #13877
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alalek
reviewed
Feb 21, 2019
| if cv.waitKey(1) & 0xFF == ord('q'): | ||
| # Display the resulting frame | ||
| cv.imshow('frame',gray) | ||
| if cv.waitKey(1) & 0xFF == ord('q') or not ret: |
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& 0xFF
Not needed anymore with waitKey().
| # Our operations on the frame come here | ||
| gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY) | ||
| # if frame is read correctly ret is True | ||
| if ret: |
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What is about this?
if not ret:
print("Can't receive frame (stream end?). Exiting...")
break
At least we don't need to complicate condition below.
| @@ -25,17 +25,21 @@ import numpy as np | |||
| import cv2 as cv | |||
|
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| cap = cv.VideoCapture(0) | |||
|
|
|||
| if not cap.isOpened: | |||
| print("Cannot open VideoCapture") | |||
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good practise in tutorial?