The Ostu algorithm of graduation project---and its binary value

two-valued Ostu algorithm:


#include "stdafx.h"
#include <stdio.h>
#include <cv.h>
#include
#include <math.h>
int Otsu (iplimage* src);
  
int _tmain (int argc, _tchar* argv[])
{  
iplimage* img = cvloadimage ("Lena.jpg", 0);
iplimage* DST = cvcreateimage (Cvgetsize (IMG), 8, 1);
int threshold = Otsu (IMG);
  
cvthreshold (IMG, DST, threshold, 255, cv_thresh_binary);
  
  
Cvnamedwindow ("img", 1);
cvshowimage ("img", DST);
  
  
Cvwaitkey (-1);
  
cvreleaseimage (&IMG);
cvreleaseimage (&DST);
  
Cvdestroywindow ("DST");
return 0;
}  
  
int Otsu (iplimage* src)
{    
int height=src->height;
int width=src->width;
Long size = height * width;
  
//histogram
float histogram[256] = {0};
for (int m=0; m < height; m++)
    {    
unsigned char* p= (unsigned char*) Src->imagedata + src->widthstep * m;
for (int n = 0; n < width; n++)
        {    
histogram[int (*p++)]++;
        }    
    }    
  
int threshold;
long SUM0 = 0, sum1 = 0;//storage foreground gray sum and background gray sum
long cnt0 = 0, cnt1 = 0;//total number of foreground and total number of backgrounds
double w0 = 0, w1 = 0;//ratio of the entire image to the foreground and background
Double u0 = 0, u1 = 0; Average grayscale of foreground and background
double variance = 0;//maximum Inter-class variance
int I, J;
double u = 0;
double maxvariance = 0;
For (i = 1; i < i++)//traversing each pixel at a time
    {    
SUM0 = 0;
sum1 = 0;
cnt0 = 0;
cnt1 = 0;
w0 = 0;
W1 = 0;
For (j = 0; J < i; j + +)
        {  
cnt0 + = Histogram[j];
SUM0 + = J * Histogram[j];
        }  
  
u0 = (double) sum0/cnt0;
w0 = (double) cnt0/size;
  
For (j = i; J <= 255; j + +)
        {  
cnt1 + = Histogram[j];
Sum1 + = J * Histogram[j];
        }  
  
u1 = (double) sum1/cnt1;
W1 = 1-w0;//(double) cnt1/size;
  
u = u0 * w0 + u1 * W1;//average grayscale of image
printf ("U =%f\n", u);
//variance = w0 * POW ((u0-u), 2) + W1 * POW ((u1-u), 2);
Variance = w0 * W1 * (U0-U1) * (U0-U1);
if (Variance > Maxvariance)
        {    
maxvariance = variance;
threshold = i;
        }   
    }    
  
printf ("threshold =%d\n", threshold);
return threshold;
}  

The Ostu algorithm of graduation project---and its binary value