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...