cv2 video capture code example

Example 1: opencv webcam python

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

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(1) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

Example 2: how to read video in opencv python

import numpy as np
import cv2
cap = cv2.VideoCapture('videos/wa.avi')
while(cap.isOpened()):
  ret, frame = cap.read()
  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  cv2.imshow('frame',gray)
  if cv2.waitKey(1) & 0xFF == ord('q'):
    break

cap.release()
cv2.destroyAllWindows()

Example 3: python cv2 screen capture

import numpy as np
import cv2
from PIL import ImageGrab

while True:
    img = ImageGrab.grab(bbox=(0, 1000, 100, 1100)) #x, y, w, h
    img_np = np.array(img)
    frame = cv2.cvtColor(img_np, cv2.COLOR_BGR2GRAY)
    cv2.imshow("frame", frame)
    if cv2.waitKey(1) & 0Xff == ord('q'):
        break
    
cv2.destroyAllWindows()

Example 4: cv2 get framerete video

fps = capture.get(cv2.CAP_PROP_FPS)