使用摄像头实例：

    1. #coding:utf-8
    3. import cv2
    5. def video_capture():
    6.     camera = cv2.VideoCapture(0)
    8.     while (True):
    9.         ret, frame = camera.read()
    11.         if ret == True:
    12.             image = cv2.cvtColor(frame,  cv2.COLOR_BGR2GRAY)
    13.             cv2.imshow("image", image)
    15.             if cv2.waitKey(1) & 0xFF == ord('q'):
    16.                 break
    17.         else:
    18.             print("Camera read return None")
    19.             break
    21.     if camera.isOpened() == False:
    22.         print("Can not Open Camera")
    24.     camera.release()
    25.     cv2.destroyAllWindows()
    28. if __name__ == '__main__':
    29.     video_capture()

    系统未安装python-opencv的情况下，

    1. import cv2

    会出现ImportError,但是如果使用如下操作安装opencv-python(opencv API)

    1. pip install opencv-python

    引入cv2时不会出现错误，但是摄像头会出问题，具体问题体现如下：

    • read()返回的ret永远为False，frame永远为None
    • camera.isOpened()返回永远为False
    • cvtColor，imshow等错误

    总结：opencv使用摄像头时，tensorflow环境需要卸载opencv-python并安装python-opencv

    1. pip uninstall opencv-python
    2. sudo apt install python-opencv

    https://blog.csdn.net/fangzhengshu/article/details/78530230