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)

OpenCV.js introduction

This recipe introduces a new way to develop computer vision algorithms with OpenCV using JavaScript for the World Wide Web (WWW). Before OpenCV.js, developers that needed some computer vision tasks on the web had to develop them in C++ in servers or Java applets clients, which were not optimized, but with OpenCV.js, the new paradigm of client applications using web browsers has grown with unlimited of possibilities.

In this recipe, we are going to create a very simple case where we load an image into an img HTML tag, change the color image, and present it to a canvas element.

How to do it...

Before starting to use OpenCV.js, we need a web page as a user interface. To get a user interface, we are going...