#include <stdio.h>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <stdlib.h>
#include <opencv2/opencv.hpp>
#include <iostream>


using namespace std;
using namespace cv;

uchar maxentropie(const Mat1b& src, Mat1b& dst)
{
    // Histogram
    Mat1d hist(1, 256, 0.0);
    for (int r = 0; r < src.rows; ++r) {



        for (int c = 0; c < src.cols; ++c)
            hist(src(r, c))++;

        // Normalize
        hist = hist / double(src.rows * src.cols);


    }

    // Cumulative histogram
    Mat1d cumhist(1, 256, 0.0);
    float sum = 0;
    for (int i = 0; i < 256; ++i)
    {
        sum += hist(i);
        cumhist(i) = sum;
    }

    Mat1d hl(1, 256, 0.0);
    Mat1d hh(1, 256, 0.0);

    for (int t = 0; t < 256; ++t)
    {
        // low range entropy
        double cl = cumhist(t);
        if (cl > 0)
        {
            for (int i = 0; i <= t; ++i)
            {
                if (hist(i) > 0)
                {
                    hl(t) = hl(t) - (hist(i) / cl) * log(hist(i) / cl);
                }
            }
        }

        // high range entropy
        double ch = 1.0 - cl;  // constraint cl + ch = 1
        if (ch > 0)
        {
            for (int i = t + 1; i < 256; ++i)
            {
                if (hist(i) > 0)
                {
                    hh(t) = hh(t) - (hist(i) / ch) * log(hist(i) / ch);
                }
            }
        }
    }

    // choose best threshold

    Mat1d entropie(1, 256, 0.0);
    double h_max = hl(0) + hh(0);
    uchar threshold = 0;
    entropie(0) = h_max;

    for (int t = 1; t < 256; ++t)
    {
        entropie(t) = hl(t) + hh(t);
        if (entropie(t) > h_max)
        {
            h_max = entropie(t);
            threshold = uchar(t);
            printf("%d, ", threshold);

        }

        printf("%d, ", threshold);
    }

    // Create output image
    dst = src > threshold;

    return threshold;
}