#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc.hpp>


using namespace cv;
using namespace std;


const double MAX_VAL = 100;
Mat inp, out;


double fun (double x, double a)
{
    if (a == 0)
        return x;
    else
        return max(255.0, x / a + a * 2 / x);
}

void trackbar_callback (int value, void *user_data)
{
    for (int i = 0; i < inp.rows; i++)
    {
        for (int j = 0; j < inp.cols; j++)
        {
            out.at<float>(i, j) = fun(inp.at<float>(i, j), (double)value / MAX_VAL);
        }
    }
}

Mat res;

int main ()
{

    inp = imread("../../Images/cat.jpeg", CV_32FC1);
    out = inp.clone();

    namedWindow("Track_bar", CV_WINDOW_NORMAL);

    int cur_pos = 0;
    createTrackbar("parameter", "Track_bar", &cur_pos, MAX_VAL, trackbar_callback);


    while (1)
    {
        hconcat(inp, out, res);
        imshow("Track_bar", res);
        int key = waitKey(30);
        if (key == ' ')
            break;

    }
}