[BUG] qt.qpa.plugin: Could not load the Qt platform plugin "xcb" -- fixed

[fatalfeel]

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/usr/lib/python3.7/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl.

//////////////////////or//////////////////////////////////
QObject::moveToThread: Current thread (0xe38c70) is not the object's thread (0x1ab6aa0).
Cannot move to target thread (0xe38c70)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/usr/lib/python3.7/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

///////////////////trace bug method
ldd /usr/lib/python3.7/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so
search [not found]

/////////////////// solved//////////////
sudo apt-get install python3-pyqt5
sudo apt-get install libxcb-xinerama0
sudo pip3 install pyqt5
sudo pip3 install opencv-python==3.4.10.35
sudo pip3 install labelme

[Heermosi]

I'm faced with the same , ... so called bugs? It was some thing relative to qt in Linux, may be you should submit the bug to opencv.
No not at all, you do not need anything else to make it work, just remove the damn

/usr/lib/python3.7/site-packages/cv2/qt/plugins
then everything is fine....
May be the plugin shipped with opencv was not suited for this version of QT.
And it was a particular problem when opencv and pyqt installed at the same time in Linux. No such issue detected in Windows.

[TaucherLoong]

I have the same problem for a week, you mean 'remove /usr/lib/python3.7/site-packages/cv2/qt/plugins'. How to remove? remove the whole plugins directory or all files under this directory

[TaucherLoong]

or remove the qt directory?

[YacobBY]

@TaucherLoong Delete the whole plugins directory from wherever your venv is located. In my Project using the Pycharm IDE this would be venv/lib/python3.9/site-packages/cv2/qt/plugins

[TaucherLoong]

@YacobBY Thanks a lot，it really works

[wkentaro]

Thanks for finding and sharing the solution. 👍

[fsevenm]

I'm faced with the same , ... so called bugs? It was some thing relative to qt in Linux, may be you should submit the bug to opencv. No not at all, you do not need anything else to make it work, just remove the damn

/usr/lib/python3.7/site-packages/cv2/qt/plugins then everything is fine.... May be the plugin shipped with opencv was not suited for this version of QT. And it was a particular problem when opencv and pyqt installed at the same time in Linux. No such issue detected in Windows.

In my case Ubuntu 21.04, it's in /usr/local/lib/python3.9/dist-packages/cv2/qt/plugins. And yes, removing them or moving to other folder fixed the issue.

[JPLeoRX]

Dialing in here - removing the whole plugins folder breaks opencv if you're using it in normal (not headless) mode. I feel like this bug needs a better solution.

[nick-halden]

In case you're running on a server: Check if there are any calls for graphical output like cv2.namedWindow, cv2.imshow(), ...
If so, delete them.

[trezero]

What if I want the graphical output? Is there no way to have it work with the windows? It will be really hard to know if the app is working without being able to see anything for testing

[AbdelsalamHaa]

Thanks @TaucherLoong ,
your solution worked for me :)

[Airluv]

@TaucherLoong Delete the whole plugins directory from wherever your venv is located. In my Project using the Pycharm IDE this would be venv/lib/python3.9/site-packages/cv2/qt/plugins

It really works!!!

[MarwanMagdy0]

the solution works for me but when i use the normal opencv imshow function it shows this error
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in "/home/marwan/.local/lib/python3.8/site-packages/cv2/qt/plugins"
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Aborted (core dumped)

[lixiang0]

L solved it by the blow command:

pip uninstall opencv-python
pip install opencv-python-headless

[tsrobcvai]

I solved this by installing a lower version of pyqt5

pip uninstall pyqt5
pip install pyqt5==5.10

[BoZhiStudying233]

Thanks for the solution, it worked for me!