OpenCV 网络摄像头问题

Question

每当我使用 OpenCV 尝试打开我的集成笔记本电脑摄像头时，我都会遇到错误。

例如：

import kivy
kivy.require('1.9.1')
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.camera import Camera
class MainApp(App):
    def build(self):
        return Camera(play=True,resolution = [0,0])
if __name__== "__main__":
    MainApp().run()

给出错误：

 Traceback (most recent call last):
   File "C:/Users/dell/Desktop/KIVY TEST/camera.py", line 13, in <module>
     MainApp().run()
   File "C:Program Files (x86)Python36-32libsite-packageskivyapp.py", line 800, in run
     root = self.build()
   File "C:/Users/dell/Desktop/KIVY TEST/camera.py", line 10, in build
     return Camera(play=True,resolution = [0,0])
   File "C:Program Files (x86)Python36-32libsite-packageskivyuixcamera.py", line 91, in __init__
     on_index()
   File "C:Program Files (x86)Python36-32libsite-packageskivyuixcamera.py", line 103, in _on_index
     resolution=self.resolution, stopped=True)
   File "C:Program Files (x86)Python36-32libsite-packageskivycorecameracamera_opencv.py", line 67, in __init__
     super(CameraOpenCV, self).__init__(**kwargs)
   File "C:Program Files (x86)Python36-32libsite-packageskivycorecamera__init__.py", line 70, in __init__
     self.init_camera()
   File "C:Program Files (x86)Python36-32libsite-packageskivycorecameracamera_opencv.py", line 121, in init_camera
     if self.fps <= 0:
 AttributeError: 'CameraOpenCV' object has no attribute 'fps'

另一个例子是：

import cv2

def show_webcam(mirror=False):
    cam = cv2.VideoCapture(0)
    while True:
        ret_val, img = cam.read()
        if mirror:
            img = cv2.flip(img, 1)
        cv2.imshow('my webcam', img)
        if cv2.waitKey(1) == 27:
            break  # esc to quit
    cv2.destroyAllWindows()

def main():
    show_webcam(mirror=True)

if __name__ == '__main__':
    main()

这给出了错误：

[ WARN:0] terminating async callback
Traceback (most recent call last):
  File "C:/Users/dell/Desktop/KIVY TEST/camera.py", line 26, in <module>
    main()
  File "C:/Users/dell/Desktop/KIVY TEST/camera.py", line 22, in main
    show_webcam(mirror=True)
  File "C:/Users/dell/Desktop/KIVY TEST/camera.py", line 15, in show_webcam
    cv2.imshow('my webcam', img)
cv2.error: OpenCV(4.0.0) C:projectsopencv-pythonopencvmoduleshighguisrcwindow.cpp:350: error: (-215:Assertion failed) size.width>0 && size.height>0 in function 'cv::imshow'

我几乎可以肯定这一定是我的特定笔记本电脑的问题，因为我使用的代码适用于在线其他人。

如果您知道我如何对此进行排序，那将非常有帮助！

谢谢！！

Answer 1

您正在运行 OpenCV 4。与 OpenCV 4 的兼容性已包含在 github master 分支中，但尚未通过 pypi 提供。尝试从 github 安装 kivy：

pip install https://github.com/kivy/kivy/archive/master.zip