Keyboard inputs

Now that we know how to capture a live video stream from the webcam, let's see how to use the keyboard to interact with the window displaying the video stream:

import cv2 
 
def print_howto(): 
    print("""
        Change color space of the
        input video stream using keyboard controls. The control keys are: 
            1. Grayscale - press 'g'
            2. YUV - press 'y'
            3. HSV - press 'h'
    """)
 
if __name__=='__main__': 
    print_howto() 
    cap = cv2.VideoCapture(0) 
 
    # Check if the webcam is opened correctly 
    if not cap.isOpened(): 
        raise IOError("Cannot open webcam") 
 
    cur_mode = None
    while True: 
        # Read the current frame from webcam 
        ret, frame = cap.read() 
 
        # Resize the captured image 
        frame = cv2.resize(frame, None, fx=0.5, fy=0.5, interpolation=cv2.INTER_AREA) 
 
        c = cv2.waitKey(1)
        if c == 27: 
            break 
        # Update cur_mode only in case it is different...