#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")

void KidoRange(unsigned char *out, unsigned char *in, int inHeight, int inWidth, int inChannel, unsigned char min, unsigned char max);

int main(){
    IplImage *in, *out;
    int i,j;

    in = cvLoadImage("./image640.bmp", 0);
    out = cvCreateImage(cvSize(in->width, in->height), in->depth, in->nChannels);

    KidoRange((unsigned char*)out->imageData, (unsigned char*)in->imageData, in->height, in->width, in->nChannels, 0, 200);

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

    cvReleaseImage( &in );
    cvReleaseImage( &out );

    return 0;
}

void KidoRange(unsigned char *out, unsigned char *in, int inHeight, int inWidth, int inChannel, unsigned char min, unsigned char max){
    int i, j;
    int index;
    double tmp;
    double rate;
    int range;
    
    int widthStep;

    widthStep = inWidth * inChannel;
    if(widthStep % 4 != 0){
        widthStep = widthStep + 4 - widthStep % 4;
    }

    range = abs(max - min);
    rate = (double)256 / (double)(range + 1);
    
    for(i = 0; i < inHeight; ++i){
        for(j = 0; j < inWidth; ++j){
            index = i * widthStep + j;

            if(in[index] >= min && in[index] <= max){
                tmp = (in[index] - min) * rate;
                if(tmp > 255){
                    tmp = 255;
                }
                out[index] = tmp;
            } else if(in[index] < min){
                out[index] = 0;
            } else if(in[index] > max){
                out[index] = 255;
            }
        }
    }
}