#include <stdio.h>
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"
#pragma comment(lib,"cv.lib")
#pragma comment(lib,"cxcore.lib")
#pragma comment(lib,"highgui.lib")

#define KIDO_SIZE 256
#define GRAPH_HEIGHT 512

#define KIDO_SIZE 256
#define GRAPH_HEIGHT 512

void histgram(unsigned int *out, unsigned char *in, int inHeight, int inWidth, int inChannel);
void PercentileMethod(unsigned char *out, unsigned int *histData, unsigned char *in, int inHeight, int inWidth, int inChannel, double rate);

int main(){
   IplImage *in, *out;
   unsigned int *histData;
   int i,j;
   double maxRate;
   
   in = cvLoadImage("./image640.bmp", 0);
   out = cvCreateImage(cvSize(in->width, in->height), in->depth, in->nChannels);
   
   histData = (unsigned int *)malloc(sizeof(unsigned int) * (KIDO_SIZE + 1));

   // 0初期化
   memset(histData, 0, sizeof(unsigned int) * (KIDO_SIZE + 1));
   histgram(histData, (unsigned char*)in->imageData, in->height, in->width, in->nChannels);
   PercentileMethod((unsigned char*)out->imageData, histData,(unsigned char*)in->imageData, in->height, in->width, in->nChannels, 0.3);

   cvNamedWindow("in", 1);
   cvShowImage("in", in);
   cvNamedWindow("out", 1);
   cvShowImage("out", out);
   cvWaitKey(-1);

   cvDestroyWindow("in");
   cvDestroyWindow("out");
   
   cvReleaseImage( &in );
   cvReleaseImage( &out );
   
   free(histData);


   return 0;
}


void histgram(unsigned int *out, unsigned char *in, int inHeight, int inWidth, int inChannel){
    int i, j;
    int index;

    for(i = 0; i < inHeight; ++i){
        for(j = 0; j < inWidth; ++j){
            // 入力画像の輝度値と等しい配列番号の要素をインクリメント
            index = in[i * inWidth + j];
            ++out[ index ];

            // 最大値を格納する
            if(out[KIDO_SIZE] < out[ index ]){
                out[KIDO_SIZE] = out[ index ];
            }
        }
    }
}

void PercentileMethod(unsigned char *out, unsigned int *histData, unsigned char *in, int inHeight, int inWidth, int inChannel, double rate){
    int i, j;
    int index;
    int allData = 0;
    int th;

    // ヒストグラムの合計
    for(i = 0; i < KIDO_SIZE; ++i){
        allData += histData[i];
    }

    // rate分のヒストグラムの合計値
    th = allData * rate;
    
    // rate分のヒストグラムの合計値を超えた輝度を閾値とする
    allData = 0;
    for(i = 0; i < KIDO_SIZE; ++i){
        allData += histData[i];

        if(allData > th){
            th = i;
            break;
        }
    }

    for(i = 0; i < inHeight; ++i){
        for(j = 0; j < inWidth; ++j){
            index = i * inWidth + j;

            if(in[index] > th){
                out[index] = 255;
            } else {
                out[index] = 0;
            }
        }
    }
}