ubuntu出现qt.qpa.plugin报错

问题/报错：qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in “/usr/local/lib/python3.6/dist-packages/cv2/qt/plugins” even though it was found.

在安装opencv之后，我又安装了contrib，后来忽然出现上述"xcb"错误。

sudo -H pip3 install opencv-python
sudo -H pip3 install opencv-contrib-python

卸载contrib即可解决：

sudo -H pip3 uninstall opencv-contrib-python
sudo -rm -rf /usr/local/lib/python3.6/dist-packages/~pencv_contrib_python*

卸载后，检查下cv2的版本是否正确：import cv2; cv2.__version__ 。如果有误，重装opencv即可。