Book Image

Computer Vision with OpenCV 3 and Qt5

By : Amin Ahmadi Tazehkandi
4 (1)
Book Image

Computer Vision with OpenCV 3 and Qt5

4 (1)
By: Amin Ahmadi Tazehkandi

Overview of this book

Developers have been using OpenCV library to develop computer vision applications for a long time. However, they now need a more effective tool to get the job done and in a much better and modern way. Qt is one of the major frameworks available for this task at the moment. This book will teach you to develop applications with the combination of OpenCV 3 and Qt5, and how to create cross-platform computer vision applications. We’ll begin by introducing Qt, its IDE, and its SDK. Next you’ll learn how to use the OpenCV API to integrate both tools, and see how to configure Qt to use OpenCV. You’ll go on to build a full-fledged computer vision application throughout the book. Later, you’ll create a stunning UI application using the Qt widgets technology, where you’ll display the images after they are processed in an efficient way. At the end of the book, you’ll learn how to convert OpenCV Mat to Qt QImage. You’ll also see how to efficiently process images to filter them, transform them, detect or track objects as well as analyze video. You’ll become better at developing OpenCV applications.
Table of Contents (19 chapters)
Title Page
Dedication
Packt Upsell
Foreword
Contributors
Preface

Introduction to QML


As mentioned in the introduction, QML has a JSON-like structure that be used to describe the elements on a user interface. A QML code imports one or more libraries and has a root element that contains all of the other visual and non-visual elements. The following is an example of a QML code that results in the creation of an empty window (ApplicationWindow type) with a specified width, height, and title:

    import QtQuick 2.7 
    import QtQuick.Controls 2.2 
 
    ApplicationWindow 
    { 
      visible: true 
      width: 300 
      height: 500 
      title: "Hello QML" 
    } 

Each import statement must be followed with a QML library name and version. In the preceding code, two of the main QML libraries that include most of the default types are imported. For instance, ApplicationWindow is defined inside the QtQuick.Controls 2.2 library. The only source of truth for existing QML libraries and their correct versions is the Qt documentation, so make sure to always refer...