#ifndef WIDGET_H
#define WIDGET_H
 
#include <QWidget>
#include<opencv2/opencv.hpp>
using namespace cv;
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
private slots:
    void TheMax(Mat Input_iamge);
    void TheMean(Mat Input_iamge);
    void TheMeightedMean(Mat Input_iamge);
    void UI_init();
private:
    Ui::Widget *ui;
};
#endif // WIDGET_H

#include "widget.h"
#include "ui_widget.h"
 
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    UI_init(); //init ui
 
    Mat image_1=imread("D:/program/Qt/Qt5+opencv/108homework/me.png");
    ui->image1->setPixmap(QPixmap("D:/program/Qt/Qt5+opencv/108homework/me.png"));
 
    TheMax(image_1);
    ui->image2->setPixmap(QPixmap("D:/program/Qt/Qt5+opencv/108homework/image_2.png"));
 
    TheMean(image_1);
    ui->image3->setPixmap(QPixmap("D:/program/Qt/Qt5+opencv/108homework/image_3.png"));
 
    TheMeightedMean(image_1);
    ui->image4->setPixmap(QPixmap("D:/program/Qt/Qt5+opencv/108homework/image_4.png"));
}
 
Widget::~Widget()
{
    delete ui;
}
void Widget::TheMax(Mat Input_iamge)
{
     int width = Input_iamge.cols;
     int height = Input_iamge.rows;
     Mat image_2(height,width,CV_8UC1);
     for (int j = 0; j < height; j++)
     {
      for (int i = 0; i < width; i++)
      {
       int b  = Input_iamge.at<Vec3b>(j, i)[0];
       int g  = Input_iamge.at<Vec3b>(j, i)[1];
       int r  = Input_iamge.at<Vec3b>(j, i)[2];
       image_2.at<uchar>(j, i) = saturate_cast<uchar>(max(r,max(b,g)));
      }
     }
     imwrite("D:/program/Qt/Qt5+opencv/108homework/image_2.png", image_2);
}
void Widget::TheMean(Mat Input_iamge)
{
    int width = Input_iamge.cols;
    int height = Input_iamge.rows;
    Mat image_3(height,width,CV_8UC1);
    for (int j = 0; j < height; j++)
    {
     for (int i = 0; i < width; i++)
     {
      int b  = Input_iamge.at<Vec3b>(j, i)[0];
      int g  = Input_iamge.at<Vec3b>(j, i)[1];
      int r  = Input_iamge.at<Vec3b>(j, i)[2];
      image_3.at<uchar>(j, i) = saturate_cast<uchar>((r+g+b)/3);
     }
    }
    imwrite("D:/program/Qt/Qt5+opencv/108homework/image_3.png", image_3);
}
void Widget::TheMeightedMean(Mat Input_iamge)
{
    int width = Input_iamge.cols;
    int height = Input_iamge.rows;
    Mat image_4(height,width,CV_8UC1);
    for (int j = 0; j < height; j++)
    {
     for (int i = 0; i < width; i++)
     {
      int b  = Input_iamge.at<Vec3b>(j, i)[0];
      int g  = Input_iamge.at<Vec3b>(j, i)[1];
      int r  = Input_iamge.at<Vec3b>(j, i)[2];
      image_4.at<uchar>(j, i) = saturate_cast<uchar>(0.299*r + 0.587*g + 0.114*b);
     }
    }
    imwrite("D:/program/Qt/Qt5+opencv/108homework/image_4.png", image_4);
}
void Widget::UI_init()
{
    ui->image1->setFrameShape(QFrame::Box);
    ui->image1->setFrameShadow(QFrame::Sunken);
    ui->image1->setLineWidth(5);
    ui->image1->setLineWidth(10);
 
    ui->image2->setFrameShape(QFrame::Box);
    ui->image2->setFrameShadow(QFrame::Sunken);
    ui->image2->setLineWidth(5);
    ui->image2->setLineWidth(10);
 
    ui->image3->setFrameShape(QFrame::Box);
    ui->image3->setFrameShadow(QFrame::Sunken);
    ui->image3->setLineWidth(5);
    ui->image3->setLineWidth(10);
 
    ui->image4->setFrameShape(QFrame::Box);
    ui->image4->setFrameShadow(QFrame::Sunken);
    ui->image4->setLineWidth(5);
    ui->image4->setLineWidth(10);
 
}