Question

我想使用我的笔记本电脑网络摄像头通过以下代码捕获图片：

import cv2
cap = cv2.VideoCapture(1)
while(True):
    ret, frame = cap.read()
    cv2.imshow('frame', frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()


cv2.destroyAllWindows()

但是会引发此错误：

cv2.imshow（'frame'，frame）cv2.error：OpenCV（4.0.0） C：\ projects \ opencv-python \ opencv \ modules \ highgui \ src \ window.cpp：350：错误：（-215：声明失败）size.width> 0 && size.height> 0 in 函数'cv :: imshow'

如何解决此错误？

Answer 1

当if user is not None: # authenticate the user auth.login(request, user) # Fetch additional information about the user # fetching presonal-Information try: personal_info = PersonalInformation.objects.get(user_id=user.id) except ObjectDoesNotExist: personal_info = None return redirect('dashboard', personal_info) else: messages.error(request, 'Invalid credentials') return redirect('login') else: return render(request, 'pages/login.html')无法从摄像机或流中获取帧时，它不会引发错误，但会在OpenCV中返回False（返回状态），因此您应进行检查。它还会在ret中返回None，并且frame不能显示imshow-它没有宽度和高度-因此您会遇到None

据我所知，笔记本电脑的网络摄像头大多是数字size.width>0 && size.height>0，而不是0

该功能可用于我的笔记本电脑网络摄像头

编辑：，如Dave W. Smith在评论中所说：一些笔记本电脑可能需要一些时间来发送正确的图像，然后此处的版本不会退出循环

import cv2

cap = cv2.VideoCapture(0) # zero instead of one

while True:
    ret, frame = cap.read()

    if not ret: # exit loop if there was problem to get frame to display
        break

    cv2.imshow('frame', frame)

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

cap.release()
cv2.destroyAllWindows()

Answer 2

import numpy as np
import cv2

cap = cv2.VideoCapture(0)  #it can be one also...but generally zero

while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()
    cv2.imshow('Capture', frame)
    if cv2.waitKey(25) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

尝试这个...适用于我的...确保已安装numpy

使用cv2.VideoCapture捕获图片

2 个答案: