Getting error in cv::imshow() - ASSERT: "false" in file qasciikey.cpp, line 501

Question

I am getting this error whenever I call cv::waitKey():

ASSERT: "false" in file qasciikey.cpp, line 501

I am not sure why I am getting this error. I am running on an Ubuntu Server 14.04 EC2 instance connected through MobaXterm on Windows. If I run all of the same code on a normal ubuntu machine, all works great.

This is the line where this happens:

char key = cvWaitKey(33);

When i originally build OpenCV I used the flag WITH_QT=ON. I simply ended up building OpenCV with WITH_QT=OFF and it worked great. — Georgi Angelov, Mar 10 '16 at 04:41
I got the same error in the same circumstance. It does not always happen. — djsg, Apr 10 '19 at 06:36

score 13 · Answer 1 · answered Jan 21 '20 at 08:53

13

A workaround in MobaXterm is to uncheck "Unix-compatible keyboard" in X11 settings.

answered Jan 21 '20 at 08:53

hplio

131
1
2

score 4 · Answer 2 · answered Sep 10 '19 at 04:41

4

Try this.

pip install qtconsole

I solve the problem.

answered Sep 10 '19 at 04:41

hyunji Yoo solteee

39
4

score 2 · Answer 3 · answered Dec 13 '18 at 10:19

I am not trying to get the glory here but I think this deserves a proper answer.

As @George mentioned in the comment when my input was not from an English keyboard but used some other locale then this error occurs. I have seen other proposed reasons for this error but I guess this is a quite usual case since the error reports:

ASSERT: "false"

Getting error in cv::imshow() - ASSERT: "false" in file qasciikey.cpp, line 501

3 Answers3

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