python - 在 cv2 代码执行期间，MacOS 相机不可见

Question

下面是我的代码，我尝试在 jupyter notebook 上以及通过终端运行我的代码。但是当执行主要功能时，我收到以下错误（附照片）并且相机灯打开。此 python 文件也已形成，但处于无响应状态。当这个 python 文件被强制退出时，相机灯就会关闭。

MacOS 版本 -> MacOS Big Sur 11.0.1

如何修复错误并成功运行代码？

import imutils
import numpy as np

# global variables
bg = None

def run_avg(image, aWeight):
  global bg

  if bg is None:
    image.copy().astype("float")
    return

  cv2.accumulateWeighted(image, bg, weight)

def segment(image, threshold=25):
    global bg
    
    diff = cv2.absdiff(bg.astype("uint8"), image)

    
    thresholded = cv2.threshold(diff, threshold, 255, cv2.THRESH_BINARY)[1]

    
    (_, cnts, _) = cv2.findContours(thresholded.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    
    if len(cnts) == 0:
        return
    else:
        
        segmented = max(cnts, key=cv2.contourArea)
        return (thresholded, segmented)


if __name__ == "__main__":
    # initialize weight for running average
    aWeight = 0.5

    # get the reference to the webcam
    camera = cv2.VideoCapture(0)

    # region of interest (ROI) coordinates
    top, right, bottom, left = 10, 350, 225, 590

    # initialize num of frames
    num_frames = 0

    # keep looping, until interrupted
    while(True):
        # get the current frame
        (grabbed, frame) = camera.read()

        # resize the frame
        frame = imutils.resize(frame, width=700)

        # flip the frame so that it is not the mirror view
        frame = cv2.flip(frame, 1)

        # clone the frame
        clone = frame.copy()

        # get the height and width of the frame
        (height, width) = frame.shape[:2]

        # get the ROI
        roi = frame[top:bottom, right:left]

        # convert the roi to grayscale and blur it
        gray = cv2.cvtColor(roi, cv2.COLOR_BGR2GRAY)
        gray = cv2.GaussianBlur(gray, (7, 7), 0)

        # to get the background, keep looking till a threshold is reached
        # so that our running average model gets calibrated
        if num_frames < 30:
            run_avg(gray, aWeight)
        else:
            # segment the hand region
            hand = segment(gray)

            # check whether hand region is segmented
            if hand is not None:
                # if yes, unpack the thresholded image and
                # segmented region
                (thresholded, segmented) = hand

                # draw the segmented region and display the frame
                cv2.drawContours(clone, [segmented + (right, top)], -1, (0, 0, 255))
                cv2.imshow("Thesholded", thresholded)

        # draw the segmented hand
        cv2.rectangle(clone, (left, top), (right, bottom), (0,255,0), 2)

        # increment the number of frames
        num_frames += 1

        # display the frame with segmented hand
        cv2.imshow("Video Feed", clone)

        # observe the keypress by the user
        keypress = cv2.waitKey(1) & 0xFF

        # if the user pressed "q", then stop looping
        if keypress == ord("q"):
            break

# free up memory
camera.release()

错误图片在这里

标签： pythonmacosopencvjupyter-notebook