Book Image

OpenCV 4 Computer Vision Application Programming Cookbook - Fourth Edition

By : David Millán Escrivá, Robert Laganiere
Book Image

OpenCV 4 Computer Vision Application Programming Cookbook - Fourth Edition

By: David Millán Escrivá, Robert Laganiere

Overview of this book

OpenCV is an image and video processing library used for all types of image and video analysis. Throughout the book, you'll work with recipes to implement a variety of tasks. With 70 self-contained tutorials, this book examines common pain points and best practices for computer vision (CV) developers. Each recipe addresses a specific problem and offers a proven, best-practice solution with insights into how it works, so that you can copy the code and configuration files and modify them to suit your needs. This book begins by guiding you through setting up OpenCV, and explaining how to manipulate pixels. You'll understand how you can process images with classes and count pixels with histograms. You'll also learn detecting, describing, and matching interest points. As you advance through the chapters, you'll get to grips with estimating projective relations in images, reconstructing 3D scenes, processing video sequences, and tracking visual motion. In the final chapters, you'll cover deep learning concepts such as face and object detection. By the end of this book, you'll have the skills you need to confidently implement a range of computer vision algorithms to meet the technical requirements of your complex CV projects.
Table of Contents (17 chapters)

Comparing colors using the strategy design pattern

Let's suppose that we want to build a simple algorithm that will identify all of the pixels in an image that have a given color. For this, the algorithm has to accept an image and a color as input and return a binary image showing the pixels that have the specified color. The tolerance with which we want to accept a color will be another parameter to be specified before running the algorithm.

In order to accomplish this objective, this recipe will use the strategy design pattern. This object-oriented design pattern constitutes an excellent way of encapsulating an algorithm in a class. It is easier than replacing a given algorithm with another one or chaining several algorithms together in order to build a more complex process. In addition, this pattern facilitates the deployment of an algorithm by hiding as much of its complexity...