ImportError: libopencv_shape.so.3.2: cannot open shared object file: No such file or directory

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I am currently trying out PYNQ-ComputerVision . After installation I tried out the 3a_Overlays-stereo_block_matching.ipynb Notebook but I get this ImportError and don’t know why. Would be awesome if you know what my problem is. Thank you in advance!

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Did you upgrade opencv? The default one that comes with image v2.5 is opencv3.2; I guess computervision is assuming you have the default opencv. So if you have upgraded your opencv, that may break their code.

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Thank you for your time and answering my question!
I checked the version and yes you are indeed right I somehow installed opencv version 3.4.3, but not intentionally haha. I used this command to install PYNQ-ComputerVision
sudo pip3 install --upgrade git+https://github.com/Xilinx/PYNQ-ComputerVision.git. I am quite a noob, but when I remember correctly the “–upgrade” flag tries to upgrade the used packages :thinking:. So I guess it upgraded opencv during the installation. I am not sure how opencv is installed in the PYNQ Platform. (cause I think it is also using the Xilinx xfOpenCV library). I also didn’t find further information in the PYNQ documentation. I would be happen, if you know where I can find the informations to dive deeper into the topic :heart_eyes:.
I tried to downgrade opencv to 3.2 with this command:
pip3 install opencv-python==3.2 but get an error message:

Could not find a version that satisfies the requirement opencv-python==3.2

I am still in the process to understand the whole system, so thank you very much for helping me!

Best greetings,

Noah :smile:

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Opencv3.2 can be installed using apt-get. In https://github.com/Xilinx/PYNQ/blob/master/sdbuild/ubuntu/bionic/aarch64/multistrap.config
find all opencv related package (searching opencv keyword), and install them. Something like:

apt-get install libopencv-calib3d-dev

Alternative way is to install from source, using the well-known cmake flow. pip install won’t upgrade any of your opencv package since we did not put opencv in the dependency list in setup.py.

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Awesome it worked. Thank you soo much rock for your help and for your precious time!!! :heart_eyes: :heart:

I actually didn’t fully understand why, I checked the opencv version with:

import cv2
print(cv2.__version__)

I still have the same version: 3.4.3

I’ve read a little into it here: https://github.com/Xilinx/PYNQ/tree/master/sdbuild
Just for my understanding how the system works:
Have I got it right that the multistrap.config is a list of supported packages for PYNQ that is not activated by default? And that this also enables the Ubuntu 18.04 host support?

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The cv2 python package is still 3.4, but I think you can manually uninstall it. Right now you have the c libraries installed as 3.2, but I guess the python package is still 3.4. The best practice is to make them consistent - you can remove all the opencv installation and just use apt-get install to install 3.2.

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Ahh okay, I understand. Thank you for your advice! :relaxed: