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

The View, QGraphicsView


We're down to the last part of The Graphics View Framework in Qt. The QGraphicsView class is a Qt Widget class that can be placed on a window to display QGraphicsScene, which itself contains a number of QGraphicsItem subclasses and/or widgets. Similar to the QGraphicsScene class, this class also provides tons of capabilities, methods, and properties to deal with the visualization part of the graphics. We'll review some of the most important ones in the following list, and then we'll learn how to subclass QGraphicsView and extend it to have several important capabilities in our comprehensive vision application, such as zoom in, zoom out, item selection, and so on. So, here are the methods and members of the QGraphicsView class that we'll need in a computer vision project:

  • The alignment and setAlignment functions can be used to set the alignment of the scene in the view. It's important to note that this will only have a visible effect when the view can completely display...