I use the pynq_v2.5 on ZCU104. I got the following error when I use opencv namedWindow and imshow function by c++. And I use ssh to control the ZCU104 by mobaxterm.
error message:
Unable to init server: Could not connect: Connection refused
(My Camera Feed:6862) : Gtk-Warning **: 13:09:38.837: cannot open display:
Does anyone know how to solve the error?
export DISPLAY=:0.0
I tried. But it doesn’t work.
Do you have a monitor connected to the DP port? Do you have a camera connected?
Yes. But it still has the same error.
Does the error result from the opencv version?
And what is the opencv lib path?
Can I install another version of opencv?
I don’t think that is the problem of the opencv version. For that error, I usually just put
export DISPLAY=:0.0
in the terminal, and then I can run program in terminal. If you are using Jupyter notebook, you need to put
!export DISPLAY=:0.0
in one of your notebook cells.
PS.
If you really want to explore opencv, you can find opencv version by
import cv2
cv2.__version__
to check its version (image v2.5 comes with 3.2). You can use the following to purge opencv
sudo apt-get autoremove -y libopencv* opencv-data python-opencv python3-opencv
Then use the cmake flow to build opencv from source. The removal and installation can take long time. I don’t recommend to you do that.
I am not using python. I use the opencv with c++.
Does the error result from the programming language I used?
How do you connect to your board? Through terminal, or SSH session? I think this might be just a normal system usage issue, not pynq-specific, so you can find something helpful on the web. e.g. How do I fix a "cannot open display" error when opening an X program after ssh'ing with X11 forwarding enabled? - Super User