[python] How do I install opencv using pip?

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 an unofficial 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 OpenCV 2.2.0, the package name for the Python bindings is "cv".The old bindings named "opencv" are not maintained any longer. You might have to adjust your code.

The official OpenCV installer does not install the Python bindings into your Python directory. There should be a Python2.7 directory inside your OpenCV 2.2.0 installation directory. Copy the whole Lib folder from OpenCV\Python2.7\ to C:\Python27\ and make sure your OpenCV\bin directory is in the Windows DLL search path.

Alternatively use the opencv-python installers at http://www.lfd.uci.edu/~gohlke/pythonlibs/#opencv.

Or Simply install

sudo pip3 install opencv-python  #for python3

sudo pip install opencv-python   #for python2

As of 10/22/2019, I think the best answer is simply

conda install opencv

It appears opencv is now in the main Anaconda channel.

To see which packages (including opencv) are in the main Anaconda channel go to Anaconda Package Lists and follow the link corresponding to your python version and os version.

Make a virtual enviroment using python3

virtualenv env_name --python="python3"

and run the following command

pip3 install opencv-python

to check it has installed correctly run

python3 -c "import cv2"

Everybody struggles initially while installing opencv. Opencv requires lot of dependencies in back-end. The best way to start with opencv is, install it in virtual environment. I suggest you to first install python anaconda distribution and create virtual environment using it. Then inside virtual environment using conda install command you can easily install opencv. I feel this is the most safe and easy approach to install opencv. The following command work for me, you can try the same.

conda install -c menpo opencv3 

Simply use this for the so far latest version 4.1.0.

pip install opencv-contrib-python==4.1.0.25

For default version use this:

pip install opencv-contrib-python

1. Open anaconda command prompt and type in below command.

   conda install -c conda-forge opencv

2. Once the 'Solving environment' is done. It will ask to download dependencies. Type 'y'.

3. It will install all the dependencies and then you are ready to code.

You could try using below command-

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.

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
try:
    import cv2
except ImportError as e:
    install(["install", "opencv-python"])
finally:
    pass

I hope this will help someone

1. Open terminal
2. Run the following command pip install --trusted-host=pypi.org --trusted-host=files.pythonhosted.org opencv-python.
3. 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"

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.

On Ubuntu you can install it for the system Python with

sudo apt install python3-opencv

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.

if you are using Pycharm navigate settings > Project:name > Project interpreter just search the module by name(in this case OpenCV-python) and install it. worked for me

You can install opencv in a simple way $ pip install opencv-python If u are having errors, you can do this $ pip install opencv-python-headless

There are two options-

pip install cv2 

or

pip install opencv-python

Hope it helps.