当我运行这个命令" cascPath = sys.argv[1] "时，我得到了错误IndexError：列表索引超出范围。

Question

我使用的是Raspberry Pi3模型B，安装了Raspbian、OpenCV2.x和Python3。

我想用我的USB摄像头拍张照片。 我发现了很多代码，但没有任何用处。我找到了一个更好的，但是当我运行命令时

cascPath = sys.argv[1]

我明白错误

Traceback (most recent call last):

File "/home/pi/test.py", line 4, in

cascPath = sys.argv[1]

IndexError: list index out of range

我只需要访问我的摄像头来拍照。

---

import cv2

import sys

cascPath = sys.argv[1]

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=5,
        minSize=(30, 30),
        flags=cv2.cv.CV_HAAR_SCALE_IMAGE
    )

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

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

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

#When everything is done, release the capture
video_capture.release()

cv2.destroyAllWindows()

这是密码