How to use OpenCV with Heroku

Question

When I attempt to deploy my application to Heroku I receive the following error:

File "/app/project/app/_ _init__.py", line 22, in <module>
File "/app/project/app/views.py", line 6, in <module>
import cv2
from .cv2 import *
File "/app/.heroku/python/lib/python3.6/site-packages/cv2/_ _init__.py", line 4, in <module>
2018-03-24T20:40:55.986945+00:00 app[web.1]: ImportError: libSM.so.6: cannot open shared object file: No such file or directory```

OpenCV is unable to find the libsm directory, however this application runs correctly locally. I have tried using a specific buildpack however those did not seem to find my site-packages folder.

How do I use openCV (python) on Heroku?

Answer 1

You have to install some dependencies, as Heroku will not automatically do it for you.

1. Add an Aptfile in your project directory and add the below file

• libsm6

• libxrender1

• libfontconfig1

• libice6

  NOTE: Aptfile should not have any .txt or any other extension. Just like the Procfile

2. Push the edited code to Github

3. In heroku dashboard,
   goto your-app --> settings --> buildpacks --> add buildpacks --> https://github.com/heroku/heroku-buildpack-apt.git
   copy and paste this link --> add buildpack

4. Deploy your app

Answer 2

New Aptfile and requirements.txt attributes works for me:

in Aptfile

libsm6
libxrender1
libfontconfig1
libice6

in requirements.txt

opencv-python-headless==4.2.0.32

---

Remember to have the Buildpack included in settings.

https://github.com/heroku/heroku-buildpack-apt