OTSU大律法的OPENCV实现

#include <iostream.h>
#include <math.h>
#include <cv.h>
#include <highgui.h>
#include <stdio.h>
#include <windows.h>
int height;
int width;

void otsu(IplImage* A, IplImage* B)
{
   long N = height * width;
   int h[256];
   double p[256],u[256],w[256];

   for(int i = 0; i < 256; i++)
   {
      h[i] = 0;
      p[i] = 0;
      u[i] = 0;
      w[i] = 0;
   }

   for(i = 0; i < height; i++)
       for(int j = 0; j < width; j++)
         for(int k = 0; k < 256; k++)
         {
            if(((uchar*)(A->imageData + A->widthStep*i))[j] == k)
            h[k]++;
         }

 

    for(i = 0; i < 256; i++)
       p[i] = h[i] / double(N);

 

    int T = 0;
    double uT,thegma2fang;
    double thegma2fang_max = -10000;

    for(int k = 0; k < 256; k++)
    {
       uT = 0;
       for(i = 0; i <= k; i++)
      {
          u[k] += i*p[i];
          w[k] += p[i];
       }

 

      for(i = 0; i < 256; i++)
         uT += i*p[i];
   
      thegma2fang = (uT*w[k] - u[k])*(uT*w[k] - u[k]) / (w[k]*(1-w[k]));

      if(thegma2fang > thegma2fang_max)
      {
          thegma2fang_max = thegma2fang;
          T = k;
       }
     }

 

     for(i = 0; i < height; i++)   //根据最佳阈值，对原图像进行处理二值化处理
        for(int j = 0; j < width; j++)
            if(((uchar*)(A->imageData + A->widthStep*i))[j] > T)
                ((uchar*)(B->imageData + B->widthStep*i))[j] = 255;
            else
               ((uchar*)(B->imageData + B->widthStep*i))[j] = 0;

}

int main(int argc, char** argv)
{
     const char* filename = argc >= 2 ? argv[1] : "lena.jpg";
     IplImage* source = cvLoadImage( filename, 0 );
     IplImage *gray = cvCreateImage(cvSize(InPut->width,InPut->height),IPL_DEPTH_8U,1);
     height = source->height;
     width = source->width;

     otsu(source,gray);

     cvNamedWindow( "Resource", 1 );
     cvShowImage( "Resource", source );
     cvNamedWindow( "Result", 1 );
     cvShowImage( "Result", gray);
     cvWaitKey(0);

     return 0;
}

转自：http://blog.sina.com.cn/s/blog_66bdb39d0100jjd3.html