如何在发现二维码时停止扫描网络摄像头，并能使其再次扫描。

Question

import cv2
import numpy as np
import pyzbar.pyzbar as pyzbar

cap = cv2.VideoCapture(0)
font = cv2.FONT_HERSHEY_PLAIN

while True:
    _, frame = cap.read()

    decodedObjects = pyzbar.decode(frame)
    for obj in decodedObjects:
        #print("Data", obj.data)
        cv2.putText(frame, str(obj.data), (50, 50), font, 2,
                    (255, 0, 0), 3)

    cv2.imshow("Frame", frame)

    key = cv2.waitKey(1)
    if key == 27:
        break

Answer 1

你可以直接停止显示frame。然后用另一个键继续。例如，你可以用另一个键来继续。

import cv2
import pyzbar.pyzbar as zbar

cap = cv2.VideoCapture(0)

font = cv2.FONT_HERSHEY_SIMPLEX 

stopped = False
delay = 1

while(True):
    ret = cv2.waitKey(delay) & 0xFF

    if ret == ord('c'): # continue
        stopped = False
        delay = 1

    if ret == ord('q'):
        break

    if stopped or (ret == ord('s')): # stop
        stopped = True
        delay = 30
        continue

    # Capture frame-by-frame
    ret, frame = cap.read()

    decodedObjects = zbar.decode(frame)
    if len(decodedObjects) > 0:
        stopped = True
        y = 50
        for obj in decodedObjects:
            #print("Data", obj.data)
            print(obj.data.decode("utf-8"))
            cv2.putText(frame, obj.data.decode("utf-8"), (50, y), font, 2, (255, 0, 0), 3)
            y += 50

    # Display the resulting frame
    cv2.imshow('frame',frame)


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