How do I install opencv using pip?

问题

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?

回答1:

Install opencv-python (which is an unofficial pre-built OpenCV package for Python) by issuing the following command:

pip install opencv-python

Make sure your command prompt has sudo elevated permissions.

回答2:

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"

回答3:

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

回答4:

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.

回答5:

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"

回答6:

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. See http://opencv.willowgarage.com/wiki/PythonInterface.

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

回答7:

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

回答8:

Open terminal
Run the following command pip install --trusted-host=pypi.org --trusted-host=files.pythonhosted.org opencv-python.
Hope it will work.

回答9:

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.