Try using opencv from apt

Author: DavidMStraub

Dockerfile

@@ -12,6 +12,7 @@ RUN apt-get update && apt-get install -y \
   unzip \
   libpq-dev postgresql-client postgresql-client-common python3-psycopg2 \
   libgl1-mesa-dev libgtk2.0-dev libatlas-base-dev \
+  libopencv-dev python3-opencv \
   && rm -rf /var/lib/apt/lists/*
 
 # set locale
@@ -39,10 +40,6 @@ RUN wget https://github.com/gramps-project/addons/archive/refs/heads/master.zip
     && unzip -p master.zip addons-master/gramps$GRAMPS_VERSION/download/PostgreSQL.addon.tgz | \
     tar -xvz -C /root/.gramps/gramps$GRAMPS_VERSION/plugins && rm master.zip
 
-# install OpenCV
-RUN python3 -m pip install --no-cache-dir --extra-index-url https://www.piwheels.org/simple \
-    opencv-python
-
 # install gunicorn
 RUN python3 -m pip install --no-cache-dir --extra-index-url https://www.piwheels.org/simple \
     gunicorn