语法错误：break不在循环内

Question

# import the necessary packages
import numpy as np
import argparse
import cv2

# initialize the current frame of the video, along with the list of
# ROI points along with whether or not this is input mode
frame = None
roiPts = []
inputMode = False
def selectROI(event, x, y, flags, param):
    # grab the reference to the current frame, list of ROI
    # points and whether or not it is ROI selection mode
    global frame, roiPts, inputMode

    # if we are in ROI selection mode, the mouse was clicked,
    # and we do not already have four points, then update the
    # list of ROI points with the (x, y) location of the click
    # and draw the circle
    if inputMode and event == cv2.EVENT_LBUTTONDOWN and len(roiPts) < 4:
        roiPts.append((x, y))
        cv2.circle(frame, (x, y), 4, (0, 255, 0), 2)
        cv2.imshow("frame", frame)
def main():
    # construct the argument parse and parse the arguments
    ap = argparse.ArgumentParser()
    ap.add_argument("-v", "--video",
        help = "path to the (optional) video file")
    args = vars(ap.parse_args())

    # grab the reference to the current frame, list of ROI
    # points and whether or not it is ROI selection mode
    global frame, roiPts, inputMode

    # if the video path was not supplied, grab the reference to the
    # camera
    if not args.get("video", False):
        camera = cv2.VideoCapture(0)

    # otherwise, load the video
    else:
        camera = cv2.VideoCapture(args["video"])

    # setup the mouse callback
    cv2.namedWindow("frame")
    cv2.setMouseCallback("frame", selectROI)

    # initialize the termination criteria for cam shift, indicating
    # a maximum of ten iterations or movement by a least one pixel
    # along with the bounding box of the ROI
    termination = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1)
    roiBox = None
# keep looping over the frames
while True:
    # grab the current frame
    (grabbed, frame) = camera.read()

    # check to see if we have reached the end of the
    # video
    if not grabbed:
        break

    # if the see if the ROI has been computed
    if roiBox is not None:
        # convert the current frame to the HSV color space
        # and perform mean shift
        hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
        backProj = cv2.calcBackProject([hsv], [0], roiHist, [0, 180], 1)

        # apply cam shift to the back projection, convert the
        # points to a bounding box, and then draw them
        (r, roiBox) = cv2.CamShift(backProj, roiBox, termination)
        pts = np.int0(cv2.cv.BoxPoints(r))
        cv2.polylines(frame, [pts], True, (0, 255, 0), 2)
# show the frame and record if the user presses a key
cv2.imshow("frame", frame)
key = cv2.waitKey(1) & 0xFF

# handle if the 'i' key is pressed, then go into ROI
# selection mode
if key == ord("i") and len(roiPts) < 4:
    # indicate that we are in input mode and clone the
    # frame
    inputMode = True
    orig = frame.copy()

    # keep looping until 4 reference ROI points have
    # been selected; press any key to exit ROI selction
    # mode once 4 points have been selected
    while len(roiPts) < 4:
        cv2.imshow("frame", frame)
        cv2.waitKey(0)

    # determine the top-left and bottom-right points
    roiPts = np.array(roiPts)
    s = roiPts.sum(axis = 1)
    tl = roiPts[np.argmin(s)]
    br = roiPts[np.argmax(s)]

    # grab the ROI for the bounding box and convert it
    # to the HSV color space
    roi = orig[tl[1]:br[1], tl[0]:br[0]]
    roi = cv2.cvtColor(roi, cv2.COLOR_BGR2HSV)
    #roi = cv2.cvtColor(roi, cv2.COLOR_BGR2LAB)

    # compute a HSV histogram for the ROI and store the
    # bounding box
    roiHist = cv2.calcHist([roi], [0], None, [16], [0, 180])
    roiHist = cv2.normalize(roiHist, roiHist, 0, 255, cv2.NORM_MINMAX)
    roiBox = (tl[0], tl[1], br[0], br[1])

# if the 'q' key is pressed, stop the loop
elif key == ord("q"):
    break
# cleanup the camera and close any open windows
camera.release()
cv2.destroyAllWindows()

if __name__ == "__main__":
    main()

运行此代码时，我在第 114 行出现错误，显示 'break is not inside the loop"...谁能帮我解决这个错误。

Answer 1

因为整个 if 都在循环之外... 只需简单地将其放入 while 循环（通过选择行并按 Tab，或在空闲时按 ctrl+]）