VC++ K-Means 图像二值化

桃扇骨 2022-06-15 04:27 224阅读 0赞

K-MEANS算法的工作原理及流程

K-MEANS算法：

输入：聚类个数k，以及包含 n个数据对象的数据库。

输出：满足方差最小标准的k个聚类

### 处理流程 ###

（1） 从 n个数据对象任意选择 k 个对象作为初始聚类中心；

（2） 根据每个聚类对象的均值（中心对象），计算每个对象与这些中心对象的距离；并根据最小距离重新对相应对象进行划分；

（3） 重新计算每个（有变化）聚类的均值（中心对象）

（4） 循环（2）到（3）直到每个聚类不再发生变化为止

k-means 算法接受输入量 k ；然后将n个数据对象划分为 k个聚类以便使得所获得的聚类满足：同一聚类中的对象相似度较高；而不同聚类中的对象相似度较小。聚类相似度是利用各聚类中对象的 [均值][Link 1]所获得一个“中心对象”（引力中心）来进行计算的。

工作过程k-means 算法的工作过程

说明如下：首先从n个数据对象任意选择 k 个对象作为初始聚类中心；而对于所剩下其它对象，则根据它们与这些聚类中心的相似度（距离），分别将它们分配给与其最相似的（聚类中心所代表的）聚类；然 后再计算每个所获新聚类的聚类中心（该聚类中所有对象的均值）；不断重复这一过程直到标准测度函数开始收敛为止。一般都采用均方差作为标准测度函数。k个聚类具有以下特点：各聚类本身尽可能的紧凑，而各聚类之间尽可能的分开。

K-MEANS 二值化，把图像分成两类，设置中心（随机选择中心点像素值， rand()%256 ）

8位灰度图像   center1 =rand()%256, center2 =rand()%256

计算各像素点到中心聚类的距离，并根据最小距离重新对相应对象进行划分，重新计算每个（有变化）聚类的均值（中心对象），循环直到每个聚类不再发生变化为止。 ![20170524101429985][]

void CShowPicView::OnKmeans() 
    {
    	CShowPicDoc* pDoc = GetDocument();
    	CDC* pDC=GetDC();
    	srand((unsigned int)time(NULL));
    	int center1=rand()%256,center2=rand()%256, distance1 = 0,distance2 =0;
    	int temp_center1 =0,temp_center2=0;
    	int i=0,j=0;
    	bool convergence = 1;
    	do{
    		double center1_count = 0,center2_count = 0, count1 = 0, count2 = 0;
    		for(j = 0; j < intHeight; j++)//将图像中各像素值及特征读取出来
    		{
    			for(i = 0; i < intWidth; i++)
    			{
    				distance1 = abs(center1-Data[j][i]);
    				distance2 = abs(center2-Data[j][i]);
    				if(distance1
         
           abs(center2-Data[j][i]) ? pDC->SetPixel(i+intWidth,j,RGB(255,255,255)) : pDC->SetPixel(i+intWidth,j,RGB(0,0,0));
    	
    	delete pDoc;
    	ReleaseDC(pDC);
    	pDoc = NULL;
    	pDC  = NULL;
    }

24位彩色度图像   center1 （R\_center1, G\_center1, B\_center1）,  center2 （ R\_center2 ,  G\_center2 ,  B\_center2 ）

计算各像素点到中心聚类的距离，并根据最小距离重新对相应对象进行划分，重新计算每个（有变化）聚类的均值（中心对象），循环直到每个聚类不再发生变化为止。

![20170524095602022][]

void CShowPicView::OnKMeansImageSegmentation() 
    {
    	CShowPicDoc* pDoc = GetDocument();
    	CDC* pDC=GetDC();
    	srand((unsigned int)time(NULL));
    
    	int R_center1=rand()%256,R_center2=rand()%256;
    	int G_center1=rand()%256,G_center2=rand()%256;
    	int B_center1=rand()%256,B_center2=rand()%256;	
    	int R_temp_center1 =0,R_temp_center2=0;
    	int G_temp_center1 =0,G_temp_center2=0;
    	int B_temp_center1 =0,B_temp_center2=0;
    	int i=0,j=0;
    	double	distance1 = 0,distance2 =0;	
    	bool convergence = 1;
    	do{
    		double R_center1_count = 0, R_center2_count = 0, R_count1 = 0, R_count2 = 0;
    		double G_center1_count = 0, G_center2_count = 0, G_count1 = 0, G_count2 = 0;
    		double B_center1_count = 0, B_center2_count = 0, B_count1 = 0, B_count2 = 0;
    		//pDC->SetPixel(x,y,RGB(pDoc->pic[y][x][0],pDoc->pic[y][x][1],pDoc->pic[y][x][2]));
    		for(j = 0; j < intHeight; j++)//将图像中各像素值及特征读取出来
    		{
    			for(i = 0; i < intWidth; i++)
    			{
    				distance1 = sqrt( pow((R_center1-pDoc->pic[j][i][0]),2)+pow((G_center1-pDoc->pic[j][i][1]),2)+pow((B_center1-pDoc->pic[j][i][2]),2) ); 
    				distance2 = sqrt( pow((R_center2-pDoc->pic[j][i][0]),2)+pow((G_center2-pDoc->pic[j][i][1]),2)+pow((B_center2-pDoc->pic[j][i][2]),2) );
    				if(distance1
        
         pic[j][i][0];   R_count1++;
    					G_center1_count+=pDoc->pic[j][i][1];   G_count1++;
    					B_center1_count+=pDoc->pic[j][i][2];   B_count1++;
    				}
    				else{
    					R_center2_count+=pDoc->pic[j][i][0];   R_count2++;
    					G_center2_count+=pDoc->pic[j][i][1];   G_count2++;
    					B_center2_count+=pDoc->pic[j][i][2];   B_count2++;
    				}
    			}
    		}
    		R_temp_center1 = int(R_center1_count/R_count1);		R_temp_center2 = int(R_center2_count/R_count2);
    		G_temp_center1 = int(G_center1_count/G_count1);		G_temp_center2 = int(G_center2_count/G_count2);
    		B_temp_center1 = int(B_center1_count/B_count1);		B_temp_center2 = int(B_center2_count/B_count2);
    		if(	  abs(R_temp_center1-R_center1)<0.1&&abs(R_temp_center2-R_center2)<0.1
    			&&abs(G_temp_center1-G_center1)<0.1&&abs(G_temp_center2-G_center2)<0.1
    			&&abs(B_temp_center1-B_center1)<0.1&&abs(B_temp_center2-B_center2)<0.1)
    			convergence = 0;
    		else
    		{
    			R_center1 = R_temp_center1;			R_center2 = R_temp_center2;
    			G_center1 = G_temp_center1;			G_center2 = G_temp_center2;
    			B_center1 = B_temp_center1;			B_center2 = B_temp_center2;
    		}
    
    	}while(convergence);
    
    	for(j = 0; j < intHeight; j++)//将图像中各像素值及特征读取出来
    		for(i = 0; i < intWidth; i++)
    		{
    			distance1 = sqrt( pow((R_center1-pDoc->pic[j][i][0]),2)+pow((G_center1-pDoc->pic[j][i][1]),2)+pow((B_center1-pDoc->pic[j][i][2]),2) ); 
    			distance2 = sqrt( pow((R_center2-pDoc->pic[j][i][0]),2)+pow((G_center2-pDoc->pic[j][i][1]),2)+pow((B_center2-pDoc->pic[j][i][2]),2) );
    			distance1 > distance2 ? pDC->SetPixel(i+intWidth,j,RGB(255,255,255)) : pDC->SetPixel(i+intWidth,j,RGB(0,0,0));
    		}
    	delete pDoc;
    	ReleaseDC(pDC);
    	pDoc = NULL;
    	pDC  = NULL;
    }

24位彩色度图像  ，分别对三通道的颜色R,G,B做单通道聚类，每通道二值化，结果会产生最多8个聚类结果。

（R\_center1，R\_center2） ，（G\_center1，G\_center2）   ，（B\_center1 ，B\_center2） ![20170524102723999][]

void CShowPicView::OnKMeansimagesegmentation() 
    {
    	CShowPicDoc* pDoc = GetDocument();
    	CDC* pDC=GetDC();
    	srand((unsigned int)time(NULL));
    	int R_center1=rand()%256,R_center2=rand()%256;
    	int G_center1=rand()%256,G_center2=rand()%256;
    	int B_center1=rand()%256,B_center2=rand()%256;		
    	int R_temp_center1 =0,R_temp_center2=0;
    	int G_temp_center1 =0,G_temp_center2=0;
    	int B_temp_center1 =0,B_temp_center2=0;
    	int i=0,j=0;
    	int	distance1 = 0,distance2 =0;	
    	bool convergence = 1;
    	do{
    		double R_center1_count = 0, R_center2_count = 0, R_count1 = 0, R_count2 = 0;
    		double G_center1_count = 0, G_center2_count = 0, G_count1 = 0, G_count2 = 0;
    		double B_center1_count = 0, B_center2_count = 0, B_count1 = 0, B_count2 = 0;
    		//pDC->SetPixel(x,y,RGB(pDoc->pic[y][x][0],pDoc->pic[y][x][1],pDoc->pic[y][x][2]));
    		for(j = 0; j < intHeight; j++)//将图像中各像素值及特征读取出来
    		{
    			for(i = 0; i < intWidth; i++)
    			{
    				distance1 = abs(R_center1-pDoc->pic[j][i][0]); distance2 = abs(R_center2-pDoc->pic[j][i][0]);
    				if(distance1
        
         pic[j][i][0];   R_count1++;
    				}
    				else{
    					R_center2_count+=pDoc->pic[j][i][0];   R_count2++;
    				}
    
    				distance1 = abs(G_center1-pDoc->pic[j][i][1]); distance2 = abs(G_center2-pDoc->pic[j][i][1]);
    				if(distance1
         
          pic[j][i][1];   G_count1++;
    				}
    				else{
    					G_center2_count+=pDoc->pic[j][i][1];   G_count2++;
    				}
    
    				distance1 = abs(B_center1-pDoc->pic[j][i][2]); distance2 = abs(B_center2-pDoc->pic[j][i][2]);
    				if(distance1
          
           pic[j][i][2];   B_count1++;
    				}
    				else{
    					B_center2_count+=pDoc->pic[j][i][2];   B_count2++;
    				}
    			}
    		}
    		R_temp_center1 = int(R_center1_count/R_count1);		R_temp_center2 = int(R_center2_count/R_count2);
    		G_temp_center1 = int(G_center1_count/G_count1);		G_temp_center2 = int(G_center2_count/G_count2);
    		B_temp_center1 = int(B_center1_count/B_count1);		B_temp_center2 = int(B_center2_count/B_count2);
    		if(	  abs(R_temp_center1-R_center1)<0.1&&abs(R_temp_center2-R_center2)<0.1
    			&&abs(G_temp_center1-G_center1)<0.1&&abs(G_temp_center2-G_center2)<0.1
    			&&abs(B_temp_center1-B_center1)<0.1&&abs(B_temp_center2-B_center2)<0.1)
    			convergence = 0;
    		else
    		{
    			R_center1 = R_temp_center1;			R_center2 = R_temp_center2;
    			G_center1 = G_temp_center1;			G_center2 = G_temp_center2;
    			B_center1 = B_temp_center1;			B_center2 = B_temp_center2;
    		}
    
    	}while(convergence);
    	int temp1=0,temp2=0,temp3=0;
    	for(j = 0; j < intHeight; j++)//将图像中各像素值及特征读取出来
    		for(i = 0; i < intWidth; i++)
    		{
    			distance1 = abs(R_center1-pDoc->pic[j][i][0])+abs(G_center1-pDoc->pic[j][i][1])+abs(B_center1-pDoc->pic[j][i][2]); 
    			distance2 = abs(R_center2-pDoc->pic[j][i][0])+abs(G_center2-pDoc->pic[j][i][1])+abs(B_center2-pDoc->pic[j][i][2]);
    			distance1 > distance2 ? pDC->SetPixel(i+2*intWidth,j,RGB(255,255,255)) : pDC->SetPixel(i+2*intWidth,j,RGB(0,0,0));
    			abs(R_center1-pDoc->pic[j][i][0])>abs(R_center2-pDoc->pic[j][i][0]) ? temp1=255 : temp1=0 ;
    			abs(G_center1-pDoc->pic[j][i][1])>abs(G_center2-pDoc->pic[j][i][1]) ? temp2=255 : temp2=0 ;
    			abs(B_center1-pDoc->pic[j][i][2])>abs(B_center2-pDoc->pic[j][i][2]) ? temp3=255 : temp3=0 ;
    			pDC->SetPixel(i+intWidth,j,RGB(temp1,temp2,temp3));
    		}
    
    //	delete pDoc;
    //	ReleaseDC(pDC);
    //	pDoc = NULL;
    //	pDC  = NULL;
    }

https://github.com/wukai0909/Image-Processing-Segmentation/tree/master

[Link 1]: http://baike.baidu.com/item/%E5%9D%87%E5%80%BC
[20170524101429985]: /images/20220615/8feff1d975ff4f3e880bba56236ce002.png
[20170524095602022]: /images/20220615/9f3eaaf0460d4dfdac6ef8bbaad3eea2.png
[20170524102723999]: /images/20220615/7609f942f5e04e3ba79bedd3f9baa50b.png