Reputation: 23
Here is my code which is running...but I didnt understood why we used:
if cv2.waitKey(1000) & 0xFF == ord('q'):
break
in the code......under display the resulting frame comment:
import numpy as np
import cv2
cap = cv2.VideoCapture('C:\\Users\\KRK\\Desktop\\Dec17thVideo.mp4')
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# Our operations on the frame come here
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame',gray)
if cv2.waitKey(1000) & 0xFF == ord('q'):
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
Upvotes: 0
Views: 497
Reputation: 3867
waitkey
displays the image for the specified number of milliseconds. Without it, you actually wouldn't be able to see anything. Then 0xFF == ord('q')
detects when the keystroke q is pressed on the keyboard.
Think of waitkey
as a pause function. After the code has been executed; at lightning speed :), waitkey
says, pause for 1000 milliseconds to display the frame. Within this, detect if the user pressed q. If q is pressed, then get outside of my infinite while loop. When this happens, then the window won't be shown anymore.
Their documentation is a good resource as well.
Upvotes: 2