解决问题：cv2.error: OpenCV(4.5.1) /tmp/pip-req-build-jhawztrk/opencv/modules/highgui/src/window.cpp:651:

OS: ubuntu16.04
IDE: pychram

error：

cv2.error: OpenCV(4.5.1) /tmp/pip-req-build-
jhawztrk/opencv/modules/highgui/src/window.cpp:651:  
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 'cvShowImage'

解决方案：

pip uninstall opencv-python-headless