ImportError: cannot import name '_registerMatType' from 'cv2.cv2'

[alexjbusch]

Trying to import cv2 in python 3.9.2 gives me the following error:

File "C:\Users\My Name\AppData\Local\Programs\Python\Python39\lib\site-packages\cv2_init_.py", line 9, in
from .cv2 import _registerMatType
ImportError: cannot import name '_registerMatType' from 'cv2.cv2' (C:\Users\My Name\AppData\Local\Programs\Python\Python39\lib\site-packages\cv2\cv2.cp39-win_amd64.pyd)

This is on Windows 10, with x86 architecture using opencv version (4.5.1.48)

[alalek]

There is mess with versions:

• _registerMatType is a part of OpenCV 4.5.4
• but you mention 4.5.1

Please ensure that you have installed one version of OpenCV only.

[alexjbusch]

yeah, uninstalling opencv-python and then reinstalling it with pip fixed this issue

[aQwus]

I solved this error on Google Colab by downloading the headless open-cv and of a version below 4.3 because backward compatibility was dropped since 4.3.0. Try the following command in Google Colab:

!pip install "opencv-python-headless<4.3"

Here's a thread from stack overflow on the same issue.

[Ahteshammm]

Thank you aQwus . It worked with !pip install "opencv-python-headless<4.3"

[EdjeElectronics]

Thanks @aQwus , that fixed it for me too! It's a little scary when your Colab code works one day and then stops working the next day 😬.

[benisalla]

I solved this error on Google Colab by downloading the headless open-cv and of a version below 4.3 because backward compatibility was dropped since 4.3.0. Try the following command in Google Colab:

!pip install "opencv-python-headless<4.3"

Here's a thread from stack overflow on the same issue.

@aQwus , thanks man that saved me to

[amiramandaa]

I solved this error on Google Colab by downloading the headless open-cv and of a version below 4.3 because backward compatibility was dropped since 4.3.0. Try the following command in Google Colab:

!pip install "opencv-python-headless<4.3"

Here's a thread from stack overflow on the same issue.

thank you very much, you save me!