Book Image

Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

By : Joseph Howse, Joe Minichino
Book Image

Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

By: Joseph Howse, Joe Minichino

Overview of this book

Computer vision is a rapidly evolving science, encompassing diverse applications and techniques. This book will not only help those who are getting started with computer vision but also experts in the domain. You’ll be able to put theory into practice by building apps with OpenCV 4 and Python 3. You’ll start by understanding OpenCV 4 and how to set it up with Python 3 on various platforms. Next, you’ll learn how to perform basic operations such as reading, writing, manipulating, and displaying still images, videos, and camera feeds. From taking you through image processing, video analysis, and depth estimation and segmentation, to helping you gain practice by building a GUI app, this book ensures you’ll have opportunities for hands-on activities. Next, you’ll tackle two popular challenges: face detection and face recognition. You’ll also learn about object classification and machine learning concepts, which will enable you to create and use object detectors and classifiers, and even track objects in movies or video camera feed. Later, you’ll develop your skills in 3D tracking and augmented reality. Finally, you’ll cover ANNs and DNNs, learning how to develop apps for recognizing handwritten digits and classifying a person's gender and age. By the end of this book, you’ll have the skills you need to execute real-world computer vision projects.
Table of Contents (13 chapters)


This chapter has dealt with video analysis and, in particular, a selection of useful techniques for tracking objects.

We began by learning about background subtraction with a basic motion detection technique that calculates frame differences. Then, we moved on to more complex and efficient background subtraction algorithms – namely, MOG and KNN – which are implemented in OpenCV's cv2.BackgroundSubtractor class.

We then proceeded to explore the MeanShift and CamShift tracking algorithms. In the course of this, we talked about color histograms and back-projections. We also familiarized ourselves with the Kalman filter and its usefulness in smoothing the results of a tracking algorithm. Finally, we put all of our knowledge together in a sample surveillance application, which is capable of tracking pedestrians (or other moving objects) in a video.

By now...