opencv assertion_error ai_generated true

cv::error: (-215:Assertion failed) !winname.empty() && namedWindow(winname, flags) == 0 in function 'imshow'

ID: opencv/highgui-window-name-duplicate

Also available as: JSON · Markdown · 中文
85%Fix Rate
82%Confidence
1Evidence
2023-04-28First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
4.5.5 active — — —
4.6.0 active — — —
4.7.0 active — — —
4.8.1 active — — —
4.9.0 active — — —

Root Cause

imshow() is called with an empty window name or a window name that conflicts with an existing named window due to duplicate creation without proper flags.

generic

中文

imshow() 调用时使用了空窗口名称，或者由于未使用正确标志重复创建而导致窗口名称冲突。

Official Documentation

https://docs.opencv.org/4.x/d7/dfc/group__highgui.html

Workarounds

  1. 95% success Always provide a non-empty, unique window name: cv::imshow("Display Window", img); or use cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); cv::imshow("MyWindow", img); 
    Always provide a non-empty, unique window name: cv::imshow("Display Window", img); or use cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); cv::imshow("MyWindow", img);
  2. 85% success Check if window exists before creating: if (cv::getWindowProperty("MyWindow", cv::WND_PROP_VISIBLE) < 0) { cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); } 
    Check if window exists before creating: if (cv::getWindowProperty("MyWindow", cv::WND_PROP_VISIBLE) < 0) { cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); }

中文步骤

  1. Always provide a non-empty, unique window name: cv::imshow("Display Window", img); or use cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); cv::imshow("MyWindow", img);
  2. Check if window exists before creating: if (cv::getWindowProperty("MyWindow", cv::WND_PROP_VISIBLE) < 0) { cv::namedWindow("MyWindow", cv::WINDOW_AUTOSIZE); }

Dead Ends

Common approaches that don't work:

  1. Calling namedWindow with a different flag like WINDOW_NORMAL every time 70% fail

    If the window name already exists, namedWindow returns non-zero but doesn't fail; imshow still sees the conflict.

  2. Using imshow without namedWindow at all 80% fail

    imshow internally calls namedWindow, so the same assertion can trigger if the name is empty.

  3. Destroying window with destroyWindow before each imshow 85% fail

    If the window name is empty, destroyWindow does nothing and imshow still fails.