图形图像实验-二值分割代码

最大类间方差分割

迭代阈值分割：进行多次循环，多次计算最佳阈值T= （m1+m2）/2;

首先随机选择一个阈值作为判断标准，遍历所有像素点，用阈值分割图像成为两组像素，G1由大于阈值的像素点组成，

G2由小于阈值的像素点组成。计算G1和G2像素的平均灰度m1和m2

新的阈值(m1+m2)/2

用阈值差作为迭代的出口

// 二值分割.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "cv.h"
#include "highgui.h"
#include <math.h>
#include <memory.h>
#include <stdio.h>
#include <iostream>
using namespace std;
int GetPixel(int i, int j,IplImage *pImage,int rgb)
{
return (int)((uchar*)(pImage->imageData+j*pImage->widthStep))[rgb*i];
//pImage->imageData是指这个图像的首地址，pImage->widthStep是每个图像所占用的字节数
}

void SetPixel(int i, int j,IplImage *pImage,float vaule,int rgb)
{
((uchar*)(pImage->imageData+j*pImage->widthStep))[rgb*i] = vaule;
}

int GetThreshold (IplImage *pImage)
{
int i,j,threshold = 128,dif=128,threshold2 ;
int totol = pImage->width*pImage->height;
cout<<"像素总数"<<totol<<endl;
while(dif>=5){
// int low[totol/2],high[totol/2];
int k=0,l =0;
int lowSum = 0,highSum = 0;
//lowM,highM,middle;
for(i = 1;i< pImage->width -1;i++)
{
for(j = 1;j< pImage ->height-1;j++)
{
if(GetPixel(i,j,pImage,1) < threshold)
{
lowSum = lowSum + GetPixel(i,j,pImage,1);
k++;
}
else
{
highSum=GetPixel(i,j,pImage,1)+highSum;
l++;
}
}
}
// for(i = 0;i<k;i++){
// lowSum = lowSum +low[i];
// }
// for(j = 0;j<l;j++){
// highSum = highSum + high[j];
// }
threshold2 = (lowSum/k+highSum/l)/2;
dif = abs(threshold2- threshold);
cout<<"未跳出"<<dif<<endl;
threshold = threshold2;
}
cout<<"跳出了"<<dif<<endl;
return threshold;
}
void GetHandleImage(int threshold,IplImage *pImage,IplImage *afterImage)
{
int i,j;
for(i = 0;i< pImage->width -1;i++)
{
for(j = 0;j< pImage ->height-1;j++)
{
if(GetPixel(i,j,pImage,1) <threshold)
{
SetPixel(i,j,afterImage,0,1);
}
else{
SetPixel(i,j,afterImage,255,1);
}

}
}
}
int main(int argc, char* argv[])
{
int threshold = 0;
const char* imagepath = "2.jpg";
IplImage *pImage;
pImage = cvLoadImage(imagepath,0);
IplImage *afterImage = cvCloneImage(pImage);
cvNamedWindow("原图");
cvShowImage( "原图", pImage);
threshold = GetThreshold(pImage);
GetHandleImage(threshold,pImage,afterImage);
cvNamedWindow("二值分割");
cvShowImage("二值分割",afterImage);
cvWaitKey();
cvReleaseImage(&pImage);
cvDestroyWindow("原图");
cvDestroyWindow("二值分割");
return 0;
}