dpkg OpenCV

Unfortunately raspbian has old packages and the linux distro model is to move slow and not update things. Unfortunately linux homebrew doesn't always work (I use homebrew on macOS and it is awesome!) on liux.

What this does

This package installs to /home/pi/.local and doesn't interact with normal debian packages from Raspbian. You can install by:

1. You will need to install my dpkg_python3 first
2. Install package with: sudo dpkg -i kevin-opencv-3.x.x.deb where 3.x.x is the current version

Package Setup

• DEBIAN
  • control (required)
  • templates (optional)
  • preinst (optional, chmod 0755)
  • postinst (optional, chmod 0755)
  • prerm (optional, chmod 0755)
  • postrm (optional, chmod 0755)

where:

preinst – this script executes before that package will be unpacked from its Debian archive (“.deb”) file. Many ‘preinst’ scripts stop services for packages which are being upgraded until their installation or upgrade is completed (following the successful execution of the ‘postinst’ script).

postinst – this script typically completes any required configuration of the package foo once it has been unpacked from its Debian archive (“.deb”) file. Often ‘postinst’ scripts ask the user for input, and/or warn the user that if they accept the default values, they should remember to go back and re-configure that package as the situation warrants. Many ‘postinst’ scripts then execute any commands necessary to start or restart a service once a new package has been installed or upgraded.

prerm – this script typically stops any daemons which are associated with a package. It is executed before the removal of files associated with the package.

postrm – this script typically modifies links or other files associated with foo, and/or removes files created by the package.

Test Raspberry Pi Camara with Video4Linux

One way to use the Raspberry Pi camera connected to the ribbon cable with OpenCV is the picamera module. You have to set it up to grab images to numpy.array then map the array to OpenCV Mat. But that has a completely different interface. Instead let's setup the Pi Camera to use the standard cv2.VideoCapture(0).

To use the standard grabbing loop cv2.VideoCapture(0) with raspicam the Video4Linux driver is needed.

1. Check prerequisites (with sudo raspi-config):
   1. Enable the camera
   2. Set large memory for gpu_mem (In Advance Options > Memmory Split set 128 MB)
2. Install v4l library from repository: sudo apt-get -y install libv4l-dev v4l-utils
3. Enable the kernel module: sudo modprobe bcm2835-v4l2
4. Test the module with: v4l2-ctl --list-devices
5. You should receive something like this:

   mmal service 16.1 (platform:bcm2835-v4l2):
   	 /dev/video0

6. Test: try to grab a single frame and check for the file test.jpg:

   v4l2-ctl --set-fmt-video=width=800,height=600,pixelformat=3
   v4l2-ctl --stream-mmap=3 --stream-count=1 --stream-to=./test.jpg

7. Info: check all available controls like brightness, contrast, etc with: v4l2-ctl --list-ctrls

If all it works well, add the module name bcm2835-v4l2 to the list of modules loaded at boot time in /etc/modules-load.d/modules.conf.

Build the Package

Get the current OpenCV number from: https://github.com/opencv/opencv/releases

You should be able to use the package already built in this repo, but if you want/need to build it, do:

./update-opencv.sh
./build-opencv.sh 3.4.0
./build-pkg.sh 3.4.0

Note, you pass the version number to build-opencv.sh so it downloads the version you want and you pass it build-pkg.sh so it gets appended onto the packages name. After, running the above commands, you should now have a shiny new debian package.

Check

You can double check your package with: dpkg-deb --info <deb file>

pi@mario opencv3 $ dpkg-deb --info libopencv3.4.0.deb
 new debian package, version 2.0.
 size 7369108 bytes: control archive=651 bytes.
     159 bytes,     7 lines   *  control              
     292 bytes,    10 lines      copyright            
       6 bytes,     1 lines   *  install              
     512 bytes,    25 lines   *  postinst             #!/bin/bash
 Package: opencv
 Architecture: all
 Maintainer: Kevin
 Depends: debconf (>= 0.5.00)
 Priority: optional
 Version: 3.4.0
 Description: Kevins computer vision library

Install the Package

Make sure to run update opencv script so you have the right libraries installed and setup.

./update-opencv.sh
sudo dpkg -i libopencv3.4.0.deb

References

• Package setup details
• Install OpenCV 3.2 Python/C++ on Raspberry PI using video4linux interface

Licenses

BSD License for OpenCV

See its license file

MIT License for build scripts

Copyright (c) 2016 Kevin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Documentation

This documentation is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.