在OSX中为python3安装opencv3

Question

So I followed this tutorial and got this error:

brew link --overwrite eigen
brew install opencv3 --with-python3 --with-contrib

wrote this in ~/.profile and sourced it:

export PYTHONPATH=$PYTHONPATH:/usr/local/Cellar/opencv3/3.0.0/lib/python3.4/site-packages
source ~/.profile
python3
Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 00:54:21) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named 'cv2'

Can someone please guide me what is wrong and how to fix it?

UPDATE:

I tried this too:

Monas-MacBook-Pro:build mona$ brew ln --force opencv3
Linking /usr/local/Cellar/opencv3/3.1.0_3... 
Error: Could not symlink bin/opencv_annotation
Target /usr/local/bin/opencv_annotation
is a symlink belonging to opencv. You can unlink it:
  brew unlink opencv

To force the link and overwrite all conflicting files:
  brew link --overwrite opencv3

To list all files that would be deleted:
  brew link --overwrite --dry-run opencv3
Monas-MacBook-Pro:build mona$ brew link --overwrite opencv3
Warning: opencv3 is keg-only and must be linked with --force
Note that doing so can interfere with building software.
Monas-MacBook-Pro:build mona$ brew link --force --overwrite opencv3
Linking /usr/local/Cellar/opencv3/3.1.0_3... 551 symlinks created

Answer 1

Since you installed OpenCV3 using Homebrew, your symlink might be corrupted.

Since the current version of OpenCV in homebrew/science is 3.1.0, your symlink probably should point to

/usr/local/Cellar/opencv3/3.1.0_3/lib/python3.5/site-packages

3.1.0_3 and python3.5 might differ on your system, so just see for yourself what directories are in /usr/local/Cellar.

BTW I didn't need to link anything after doing

brew ln --force opencv3

Answer 2

You need to link your opencv to python site-packages

Link cv.py and cv2.so using ln -s [cellar-opencv-site-packages-path] [lib-python-site-packages-path]

ln -s /usr/local/Cellar/opencv3/3.1.0_3/lib/python3.4.1/site-packages/cv.py /usr/local/lib/python3.4.1/site-packages/cv.py

ln -s /usr/local/Cellar/opencv3/3.1.0_3/lib/python3.4.1/site-packages/cv2.so /usr/local/lib/python3.4.1/site-packages/cv2.so

Path will be based on opencv and python version.

Here it is - [opencv3/3.1.0_3] and [python3.4.1]

---

In short, Copy/Link cv.py and cv2.so from /usr/local/Cellar/opencv3/[[version]]/lib/python[[version]]/site-packages/ to /usr/local/lib/python[[version]]/site-packages/

---

OR you can also add opencv site-packages to PYTHONPATH

export PYTHONPATH=$PYTHONPATH:/usr/local/Cellar/opencv3/3.1.0_3/lib/python3.4.1/site-packages/

source ~/.profile