Linux 中的 OpenCV 3.1.0 imshow 不适用于网络摄像头 (Python)

Question

我正在尝试使用官方 openCV 教程中的代码在 Ubuntu/Python 3.6:

中使用 cv2.imshow() 显示来自网络摄像头的视频

import numpy as np
import cv2
cap = cv2.VideoCapture(0)

while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()

    # Our operations on the frame come here
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    # Display the resulting frame
    cv2.imshow('frame',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

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

cv2.imshow() 出现以下错误：

The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function cvShowImage

在搜索错误时，我偶然发现了这个 post 作为类似问题的替代答案：

If you installed OpenCV using the opencv-python pip package at any point in time, be aware of the following note, taken from https://pypi.python.org/pypi/opencv-python

IMPORTANT NOTE MacOS and Linux wheels have currently some limitations:

video related functionality is not supported (not compiled with FFmpeg)

for example cv2.imshow() will not work (not compiled with GTK+ 2.x or Carbon support)

另请注意，要从其他来源安装，首先必须删除 opencv-python 包

OpenCV error: the function is not implemented

大多数其他 openCV 函数都可以正常工作。

是否有使用标准 anaconda 库的 cv2.imshow() 替代方案，这样我就不必重新编译 openCV 或使用 Python 2.7？

Answer 1

我拼凑了一个使用 matplotlib.animation 的快速而肮脏的片段，类似于 cv2.imshow() 预期对网络摄像头视频所做的事情：

import cv2
import matplotlib.pyplot as plt
import matplotlib.animation as animation
cap = cv2.VideoCapture(0)
ret, frame = cap.read()
# The following is the replacement for cv2.imshow():
fig = plt.figure() 
ax = fig.add_subplot(111)
im = ax.imshow(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB), animated=True)
def updatefig(*args):
    ret, frame = cap.read()
    im.set_array(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))
    return im
ani = animation.FuncAnimation(fig, updatefig, interval=10)
plt.show()

我发现这非常有用，因为 matplotlib.animation.FuncAnimation 可以为附加到 ax 对象，只要它们在上面的 updatefig() 函数中更新即可。

编辑：当我在 Jupyter 笔记本上工作时，我添加了以下内容以便在新 window 中观看视频：

import matplotlib
matplotlib.use('qt5agg')

Linux 中的 OpenCV 3.1.0 imshow 不适用于网络摄像头 (Python)

OpenCV 3.1.0 imshow in Linux does not work for webcam (Python)

python

linux

opencv

anaconda

webcam