Book Image

Mastering Qt 5

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.7 is an application development framework that provides a great user experience and develops full-capability applications with Qt Widgets, QML, and even Qt 3D. This book will address challenges in successfully developing cross-platform applications with the Qt framework. Cross-platform development needs a well-organized project. Using this book, you will have a better understanding of the Qt framework and the tools to resolve serious issues such as linking, debugging, and multithreading. Your journey will start with the new Qt 5 features. Then you will explore different platforms and learn to tame them. Every chapter along the way is a logical step that you must take to master Qt. The journey will end in an application that has been tested and is ready to be shipped.
Table of Contents (20 chapters)
Mastering Qt 5
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface

Implementing your OpenCV filters


Now that your development environment is ready, we can begin the fun part! We will implement three filters using OpenCV:

  • FilterOriginal: This filter does nothing and returns the same picture (lazy!)

  • FilterGrayscale: This filter converts a picture from color to grayscale

  • FilterBlur: This filter smoothes the picture

The parent class of all these filters is Filter. Here is this abstract class:

//Filter.h 
class Filter 
{ 
public: 
Filter(); 
virtual ~Filter(); 
 
virtualQImage process(constQImage& image) = 0; 
}; 
 
//Filter.cpp 
Filter::Filter() {} 
Filter::~Filter() {} 

As you can see, process() is a pure abstract method. All filters will implement a specific behavior with this function. Let's begin with the simple FilterOriginal class. Here is FilterOriginal.h:

class FilterOriginal : public Filter 
{ 
public: 
FilterOriginal(); 
    ~FilterOriginal(); 
 
QImageprocess(constQImage& image) override; 
}; 

This class inherits Filter and we override the  process...