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If you’re a newcomer and need help, check the documentation page.

When something fails

If you are attempting to debug an OpenCV program:

  • At first try to troubleshoot the problem using documentation and tutorials.
  • If it doesn’t help, search for an answer or ask a question at OpenCV Answers.
  • If you found a bug or wish to make a feature request, please see the section below.

Reporting issues / requesting features

  • First, check the issue tracker: Known bugs, often with patches or workarounds, are generally found there. If you have something to add to an existing bug, add it as a comment to the ticket, rather than posting to the mailing lists.
  • Then check the OpenCV mailing list archive and OpenCV Answers to see if someone else has asked your question or reported your bug.
  • If all the above steps failed, the best thing to do is to raise a ticket.

If you’re not sure what you found is a bug you can ask on OpenCV Answers. If the problem is confirmed as a bug, please create a ticket. They are preferred if you are posting about a bug because they will be reviewed by the developers.

Asking a question

Please read before posting to any of OpenCV support forums/lists!

Do Not:

  • The following are not appropriate questions:
    • general debugging/programming questions;
    • questions about software that is not related to OpenCV;
    • asking for help with your homework.
  • Don’t contact the developers/maintainers directly.
    • The community can’t see question or answer(s) not asked/answered publicly.
    • Open Source development works best when the entire community participates in discussions and helps to answer questions.
    • Send all questions to or other corresponding mailing list, and report all bugs to the bug tracker.


Be as specific as possible, with steps to reproduce. If we can reproduce the problem, we can fix it quickly.

  • Please specify your platform (Windows 32/64bit, Linux x86/x64/ppc/…, MacOSX 32/64bit/ppc); compiler version; OpenCV version/revision; whether IPP, OpenMP, MMX, SSE … have been enabled or not, and any other information that let us reproduce the environment, identify and localize the problem.
  • A sample code reproducing the problem helps us the most. Please check samples – for the preferred style (small code size, cross-platform). There is no need to provide any project files or makefiles, if it is a short single-file sample, we could build it and run in a minute.
  • Please provide the output of  cv::getBuildInformation()  function every time you report a bug about the trunk version of OpenCV. May be the problem is in your build settings, so the log can greatly help us.
  • If your application is complex, and the problem happens somewhere in the middle, often it is still possible to create a short standalone sample:
    • First, capture and store the data that you pass to the function using FileStorage.
    • Then copy the function call and put the corresponding reading from FileStorage in front of it.
  • Describe exactly what you were doing or are trying to do, and exactly what, if anything, went wrong. If you say, “OpenCV doesn’t work!” we can’t help you.
  • As appropriate, also include your:
    • backtraces;
    • relevant config files;
    • screenshots or videos to demonstrate the problem.