The Robot Operating System (ROS) is widely used in Robotics. But, the different available ROS distributions can lead to software version conflicts. For example, Ubuntu 18.04 uses ROS Melodic, based on Python 2.7. Ubuntu 20.04 uses ROS Noetic, which is based on Python 3. Oftentimes, our ROS master needs to be an older ROS version to have specific hardware driver support. In this article, I will show you how to keep a ROS Melodic master together with more recent ROS distributions on the same machine.

David Millán Escrivá was eight years old when he wrote his first program on an 8086 PC with BASIC language, which enabled the 2D plotting of BASIC equations. He started with his computer development relationship and created many applications and games. In 2005, he completed his studies in IT from the Universitat Politécnica de Valencia with honors in human-computer interaction supported by Computer Vision with OpenCV (v0.96). He had a final project based on this subject and published it on HCI Spanish Congress. In 2014, he completed his Master's degree in artificial intelligence, computer graphics, and pattern recognition, focusing on pattern recognition and computer vision.

Michael Beyeler is an Assistant Professor at the University of California, Santa Barbara, where he is working on computational models of bionic vision in order to improve the perceptual experience of blind patients implanted with a retinal prosthesis ("bionic eye"). His work lies at the intersection of neuroscience, computer engineering, computer vision, and machine learning. Michael is the author of four programming books focusing on computer vision and machine learning. He is also an active contributor to several open-source software projects, and has professional programming experience in Python, C/C, CUDA, MATLAB, and Android. Michael received a Ph.D. in Computer Science from the University of California, Irvine as well as a M.Sc. in Biomedical Engineering and a B.Sc. in Electrical Engineering from ETH Zurich, Switzerland.

In this tutorial you will learn how to install OpenCV 4 on your Ubuntu system. OpenCV 4 has not been officially released yet; however, a release is expected in autumn 2018. In the meantime, we can compile and install OpenCV 4 from source using the pre-release on GitHub. Once OpenCV 4 is officially released I will update this blog post as well. So, why bother installing OpenCV 4? You may want to consider installing OpenCV 4 for further optimizations, C 11 support, more compact modules, and many improvements to the Deep Neural Network (DNN) module.