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I need to install
cv2
for a script that has been written for me. I tried
pip install cv2
and
pip install open_cv
and got the same problem - a warning message from
dist.py
and complains about
zlib
being not found. No cv2 installed. I also tried
pyopenvc
and
pip install opencv-python
.
So, I went to the opencv site and downloaded the relevant exe. Ran it - generated a heap of subdirectories and a make file and stuff.
What do I do now?
Install
opencv-python
(which is the
official
pre-built OpenCV package for Python) by issuing the following command:
pip install opencv-python
–
–
run the following command by creating a virtual enviroment using python 3 and run
pip3 install opencv-python
to check it has installed correctly run
python3 -c "import cv2"
In pip package management, there are 4 different OpenCV packages all using the same namespace, cv2. Although they are not officially supported by OpenCV.org, they are commonly used in developers' community. You could install any of them using the following command:
pip install PACKAGE_NAME
where PACKAGE_NAME can be
opencv-python (only contains main modules)
opencv-contrib-python (contains both main and contrib modules)
opencv-python-headless (same as opencv-python but without GUI functionality)
opencv-contrib-python-headless (same as opencv-contrib-python but without GUI functionality)
You should only install one of them depending on your needs. If you accidentally installed multiple of them in the same environment, you can remove them using pip uninstall before installing the correct one again.
For more details, you can refer to the project description of OpenCV on Wheels.
As of 2021, all of these 4 packages are official OpenCV projects. Source: OpenCV Website.
To Install the Current Latest version of OpenCV then use the below commands:
Use this Command:
pip install --upgrade opencv-python
If you're facing problem in above command then try this :
pip install --upgrade opencv-contrib-python
To check the version of installed OpenCV:
import cv2
print(cv2.__version__)
Simply use this for the so far latest version 4.1.0.
pip install opencv-contrib-python==4.1.0.25
For the default version use this:
pip install opencv-contrib-python
If you have a new Raspberry Pi and want to install OpenCV then this tutorial would be a good choice.
For Ubuntu/Linux users:
sudo apt install python3-opencv
Everybody struggles initially while installing OpenCV. OpenCV requires a lot of dependencies in the backend. The best way to start with OpenCV is, install it in a virtual environment. I suggest that you use the Python Anaconda distribution and create a virtual environment using it. Then inside the virtual environment, you can install OpenCV using this command:
conda install -c conda-forge opencv
–
To install open_cv you can go to this website or do this,
pip install opencv-contrib-python --upgrade
pip install opencv-python
You can test it by:
C:\> python
>>> import cv2
>>> print(cv2.__version__)
'4.5.1' # your version may be a newer one
Open anaconda command prompt and type in below command.
conda install -c conda-forge opencv
Once the 'Solving environment' is done. It will ask to download dependencies. Type 'y'.
It will install all the dependencies and then you are ready to code.
I recommend this for Python 3: Please install it this way with pip
pip3 install opencv-python
This will download and install the latest version of OpenCV.
pip install opencv-contrib-python
It will basically download the compatible version. If this command fails, you could upgrade you pip using below command-
python -m pip install –upgrade pip
If you need a pictorial guide, head over to Simple Steps to Install OpenCV in Windows
You can also try installing OpenCV from prebuilt binaries from the official OpenCV site.
Open terminal
Run the following command
pip install --trusted-host=pypi.org --trusted-host=files.pythonhosted.org opencv-python.
Hope it will work.
As a reference it might help someone... On Debian system I hard to do the following:
apt-get install -y libsm6 libxext6 libxrender-dev
pip3 install opencv-python
python3 -c "import cv2"
Installing cv2 or opencv-python using pip is sometimes a problem. I was having the same problem of installing cv2 with pip. The installation wasn't a problem the problem was to import cv2 after installation. I was getting an Import Error so to fix this i import main from pip to install opencv-python. Try to run the following code in your python file then opencv-python will be installed
from pip._internal import main as install
import cv2
except ImportError as e:
install(["install", "opencv-python"])
finally:
I hope this will help someone
–
In case you use aarch64 platform with ARM64 cpu - and/or docker
On a development board on ARM64, no python-opencv version were found at all
version: NONE.
I've had to build from source. This allowed to include CUDA support.
In my case it was already available on the board but it wasn't found on the development environment.
If compiling from source is out of reach, there are Dockers
Of course compiling will take some time (few hours on ARM core), but it is worthy process to know as most open source tools can be built this way in case of issues.
I've had this problem in Google Colab, It only worked with this specific package version.
!pip install "opencv-python-headless<4.3"
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