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)

Modifying the application

Let's open the Cameo.py file, which contains the Cameo class that we last modified in Chapter 3, Processing Images with OpenCV. This class implements an application that works well with regular cameras. We do not necessarily want to replace this class, but rather we want to create a variant of it that changes the implementations of some methods in order to work with depth cameras instead. For this purpose, we will make a subclass, which inherits some of the Cameo behaviors and overrides other behaviors. Let's call it a CameoDepth subclass. Add the following line to Cameo.py (after the Cameo class and before the __main__ code block) in order to declare CameoDepth as a subclass of Cameo:

class CameoDepth(Cameo):

We will override or reimplement the __init__ method in CameoDepth. Whereas Cameo instantiates our CaptureManager class with a device...