qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/surbhi/.local/lib/python3.8/site-packages/cv2/qt/plugins" even though it was found.

[surbhi1986]

Hi I was using mmdetection for custom data, after training i saved the model.
But during testing on single image i am getting error during show which is given please. Please help guys.

QObject::moveToThread: Current thread (0x3d9b720) is not the object's thread (0x5af24f0).
Cannot move to target thread (0x3d9b720)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/surbhi/.local/lib/python3.8/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.

Aborted (core dumped)

[asmorkalov]

The error message means that OpenCV cannot initialize UI session, e.g. the program started over SSH without X forwarding. Alternative reason: mix of different Qt versions in the same app. Please ensure that you have X forwarding enabled, if you use SSH and provide ldd tool output for OpenCV binary (.so file in package).

[asmorkalov]

Also please check this thread: https://forum.qt.io/topic/119109/using-pyqt5-with-opencv-python-cv2-causes-error-could-not-load-qt-platform-plugin-xcb-even-though-it-was-found

[skvark]

There is most likely a conflicting Qt installation somewhere. Installing opencv-python-headless instead of opencv-python usually fixes this. If GUI features are needed (imshow), then the conflicting Qt (such as PyQt) needs to be removed.

[shuang1204]

我安装完opencv-python-headless，又出现了新的问题，cv2.error: OpenCV(4.5.1) /tmp/pip-req-build-tk9iuyva/opencv/modules/highgui/src/window.cpp:634: error: (-2:Unspecified error) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function 'cvNamedWindow
'请问该怎么解决呀@Olli-Pekka Heinisuo skvark

[asmorkalov]

@shuang1204 opencv-python-headless is OpenCV version built without UI support and "The function is not implemented" exception is designed behavior. Use opencv-python package, if you need UI support.

[kivancagaogluu]

There is most likely a conflicting Qt installation somewhere. Installing opencv-python-headless instead of opencv-python usually fixes this. If GUI features are needed (imshow), then the conflicting Qt (such as PyQt) needs to be removed.

This works on Ubuntu 21.10 Python 3.9.7 PyQt5 5.15.6

[swetapandey-12]

Error is solve but what if we import cv2 for futher use , it showing module not found