opencv histogram equalize, CDF graph 출력

1. histogram (PDF) 구하고
2. CDF 구하고
3. Y(imageout) = CDF(imagein)

#pragma warning(disable: 4819)

#include "opencv2/opencv.hpp"

#include <iostream>

using namespace cv;

using namespace std;

int main(void)

{

    Mat src = imread("lenna.bmp", IMREAD_GRAYSCALE);if (src.empty()) {      cerr << "Image load failed!" << endl;       return -1;  }

    

    int hist[256] = { 0, };

    for (int j = 0; j < src.rows; j++) {

        for (int i = 0; i < src.cols; i++) {

            hist[src.at<uchar>(j,i)]++;

        }

    }

    int hist_max = 0;

    for (int i = 0; i < 256; i++) {

        if (hist[i] > hist_max)

            hist_max = hist[i];

    }

    Mat histogram_original;

    histogram_original.create(256,256, CV_8U);

    histogram_original.setTo(0);

    int N=0;

    for (int i = 0; i < 256; i++) {

        int v = (double) (255.* hist[i])/ hist_max;

        v = cvRound(v);

        for (int j = 0; j < v; j++) {

            histogram_original.at<uchar>(255-j, i) = 255;

        }

    }

    int CDF[256] = { 0, };

    CDF[0] = 0;

    for (int i = 1; i < 256; i++) {

        CDF[i] = hist[i] + CDF[i - 1];

    }

    //CDF normalize

    for (int i = 1; i < 256; i++) {

        CDF[i] = cvRound(255.*CDF[i]/CDF[255]);

    //  CDF[i] = 255.*CDF[i] / CDF[255];

    }

    Mat CDFdrawing;

    CDFdrawing.create(256, 256, CV_8U);

    CDFdrawing.setTo(255);

    for (int i = 0 ; i < 256; i++) {

        line(CDFdrawing, Point(i, 255 - CDF[i]), Point(i, 255 - CDF[i]), 0);

    }

    //imshow("dst", dst);

    //CDF function Y(output) = CDF(input)

    Mat src2 = src.clone();

    Mat dst(src2.rows, src2.cols, src2.type());

    for (int i = 0; i < src2.rows; i++) {

        for (int j = 0; j < src2.cols; j++) {

            dst.at<uchar>(j, i) = CDF[(uchar)src2.at<uchar>(j, i)];

        }

    }

    imshow("src", src);

    imshow("histogram_original", histogram_original);

    imshow("CDFdrawing", CDFdrawing);

    imshow("dst", dst);

    //check equalized Image historam, CDF

    

    int hist2[256] = { 0, };

    for (int j = 0; j < dst.rows; j++) {

        for (int i = 0; i < dst.cols; i++) {

            hist2[dst.at<uchar>(j, i)]++;

        }

    }

    int hist2_max = 0;

    for (int i = 0; i < 256; i++) {

        if (hist2[i] > hist2_max)

            hist2_max = hist2[i];

    }

    Mat histogram_equalized;

    histogram_equalized.create(256, 256, CV_8U);

    histogram_equalized.setTo(0);

    int N2 = 0;

    for (int i = 0; i < 256; i++) {

        int v = (double)(255.* hist2[i]) / hist2_max;

        v = cvRound(v);

        for (int j = 0; j < v; j++) {

            histogram_equalized.at<uchar>(255 - j, i) = 255;

        }

    }

    int CDF2[256] = { 0, };

    CDF2[0] = 0;

    for (int i = 1; i < 256; i++) {

        CDF2[i] = hist2[i] + CDF2[i - 1];

    }

    //CDF normalize

    for (int i = 1; i < 256; i++) {

        CDF2[i] = cvRound(255.*CDF2[i] / CDF2[255]);

        //  CDF[i] = 255.*CDF[i] / CDF[255];

    }

    Mat CDFdrawing2;

    CDFdrawing2.create(256, 256, CV_8U);

    CDFdrawing2.setTo(255);

    for (int i = 0; i < 256; i++) {

        line(CDFdrawing2, Point(i, 255 - CDF2[i]), Point(i, 255 - CDF2[i]), 0);

    }

    imshow("histogram_equalized", histogram_equalized);

    imshow("CDF_equalized", CDFdrawing2);

    waitKey(0);

    return 0;

}