Question

我需要在python中使用cv2

理解cv2.waitkey（）

faceCascade = cv2.CascadeClassifier(cascPath)

video_capture = cv2.VideoCapture(0)

while True:
    # Capture frame-by-frame
ret, frame = video_capture.read()

gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

faces = faceCascade.detectMultiScale(
    gray,
    scaleFactor=1.1,
    minNeighbors=8,
    minSize=(40, 40),
    #flags=cv2.cv.CV_HAAR_SCALE_IMAGE
    flags = 0
)   

# Draw a rectangle around the faces
for (x, y, w, h) in faces:
    cv2.rectangle(gray, (x, y), (x+w, y+h), (0, 255, 0), 2)

# Display the resulting frame
cv2.imshow('Video', gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
    break
if cv2.waitKey(1) & 0xFF == ord('b'):
    cv2.imwrite('example.png',gray)

cv2.waitKey()当我按b时它不会保存图片但是按q工作。请帮忙！

Answer 1

你正在两次调用waitKey（）。使用您的代码，按任意键但q然后按b它将保存图像。

只调用waitKey（1）一次，并将结果保存在变量中，然后测试该变量，例如：

keypress = cv2.waitKey(1)
if keypress & 0xFF == ord('q'):
    break
if keypress & 0xFF == ord('b'):
    cv2.imwrite('example.png',gray)

cv2.waitkey（1）没有在opencv python中运行

1 个答案: