ValueError: not enough values

Question

我尝试了运行下面的代码，但遇到了 ValueError。我的预期输出是代码将打开四个摄像头 windows，它们都是不同的。谁能帮帮我？

下面是我的代码。

import cv2

firstframe = None

video = cv2.VideoCapture(0)

while True:
    check, frame = video.read()
    status = 0
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    gray = cv2.GaussianBlur(gray, (21, 21), 0)

    if firstframe is None:
       firstframe = gray
       continue

    delta_frame = cv2.absdiff(firstframe,gray)
    thresh_frame = cv2.threshold(delta_frame, 30, 255, cv2.THRESH_BINARY)[1]
    thresh_frame = cv2.dilate(thresh_frame, None, iterations=2)
    
    (_,cnts,_) = cv2.findContours(thresh_frame.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    for contour in cnts:
        if cv2.contourArea(contour) < 10000:
            continue
        status = 1
        (x, y, w, h) = cv2.boundingRect(contour)
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 3)

    cv2.imshow("Gray Frame", gray)
    cv2.imshow("Delta Frame", delta_frame)
    cv2.imshow("Threshold Frame", thresh_frame)
    cv2.imshow("Normal Frame", frame)

    key = cv2.waitKey(1)

    if key == ord('q'):
        break
    print(status)
    
video.release()
cv2.destroyAllWindows

我得到的错误是这样的：

 cnts = cv2.findContours(thresh_frame.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
ValueError: not enough values to unpack (expected 3, got 2)

Answer 1

cv2.findContours returns 2 件事（而不是 3 件事）。这两个是 contours,hierarchy.

从 (_,cnts,_) = cv2.findContours... 更改为 contours,hierarchy = cv2.findContours...

ValueError: not enough values

ValueError: not enough values

python

cv2