二值图贴标签算法

/*
    二值图处理 --- 贴标签法
    f(i,j) 检测图像 g(i,j) 标签图像初始值为设lab = 0
    1. 从左到右从上到下扫描f(i,j) 
    2. 如果f图像点(i,j)不为指定的值而回到
     看该点(i,j) 的在g图像的邻域内的lab值情况
     如果值都为0 则lab +=1 , g(i,j) = lab;
        如果不为0的值都相同则g(i,j) = lab；
        如果不为0的值不同即lab2>lab1 （不会出现三个不同值），g(i,j) = lab1 , 所有lab2的值也都改为lab1 ;lab = lab -1 ;
    3.扫描全部g图终止
*/
#include "stdafx.h"
void cvMark(unsigned char *arry,unsigned char *mask,int nwidth , int nheight , int threshold );
int _tmain(int argc, _TCHAR* argv[])
{
    unsigned char arry[36] = {
        0 , 1 , 0 , 0 , 0 , 0,
        0 , 1 , 0 , 1 , 1 , 0,
        0 , 0 , 1 , 0 , 0 , 0,
        0 , 0 , 0 , 0 , 0 , 0,
        0 , 1 , 1 , 0 , 1 , 1,
        0 , 1 , 0 , 1 , 0 , 0
    };
    puts("原图");
    for (int i = 0; i <6 ; ++i)
    {
        for (int j = 0; j <6; ++j)
        {
            printf("%4d",*(arry + i * 6 + j));
        }
        puts("");
    }
    puts("贴标签");
    unsigned char data[36];
    cvMark(arry,data,6,6,1);
    for (int i = 0; i <6 ; ++i)
    {
        for (int j = 0; j <6; ++j)
        {
            printf("%4d",*(data + i * 6 + j));
        }
        puts("");
    }
    getchar();
    return 0;
}

// 8 邻域标记 

void cvMark(unsigned char *arry,int *mask,int nwidth , int nheight , int threshold,int *count )

{

    //memset(mask,0,nwidth * nheight);

    int label = 0;

    int lab1,lab2 = 0 ;

    int data[4];

    //遍历顺序从左到右，从上到下

    for (int i = 0; i< nheight ; ++i)

    {

        for (int j = 0; j < nwidth ; ++j)

        {

            //f图不为threshold跳过

            if ( *(arry + i * nwidth + j)!=threshold)

                continue;

            //扫描该点在g图邻域lab值，简化运算只计算

            // i-1，i,j-1 , i+1,j-1

            // i-1 , 即可

            if ( i-1 < 0 || j -1 < 0)

                data[0] = 0;

            else

                data[0] = *(mask + (i -1) * nwidth + j -1);

            if (i-1 < 0)

                data[1] =0;

            else

                data[1] = *(mask + (i-1)*nwidth + j);

            if (i-1 < 0 || j+1>nwidth)

                data[2] = 0;

            else

                data[2] = *(mask + (i-1)*nwidth + j+1);

            if (j -1 < 0)

                data[3] = 0;

            else

                data[3] = *(mask + i *nwidth + j-1);

            lab1 = 0;

            lab2 = 0;

            for (int k = 0 ;k<4;++k)

            {

                if (data[k]!=0)

                {

                    if (lab1 ==0)

                    {

                        lab1 = data[k];

                    }

                    else if(data[k] != lab1)

                    {

                        lab2 = data[k];

                    }

                }

            }

            if (lab1 ==0 && lab2 ==0) 

            {

                // 8 邻域全为0

                label = label +1;

                *(mask + i * nwidth + j) = label;

            }

            else if (lab2 ==0)

            {

                //8邻域lab 值相同

                *(mask + i * nwidth + j) =lab1;

            }

            else

            {

                //8 邻域lab值不同

                //取较小的lab值，大lab值全部复制为小lab值

                if (lab1 > lab2)

                {

                    lab1 = lab1 ^ lab2;

                    lab2 = lab1 ^ lab2;

                    lab1 = lab1 ^ lab2;

                }

                *(mask + i * nwidth + j) =lab1;

                for (int l = 0 ; l< i*nwidth + j ; ++l)

                {

                    if ( * (mask + l) == lab2)

                    {

                        *(mask + l) = lab1;

                    }

                }

                label = label - 1 ;

            }

        }

    }

    *count = label;

}

 

 

/*

    函数：area_select

    参数：mark -- 贴标签法得到的标记图 cvmark得到

         img  -- 二值图像

         area -- 面积选择 小于area的将被删除

         nwidth   -- 图像宽度

         nheight  --- 图像高度

         count  --- 连通域个数 由cvmark得到

*/

void area_select( int * mark,unsigned char * img,int area,int nwidth,int nheight,int count)

{

    int *acc = (int *)malloc((count+1) * sizeof(int));

    memset(acc,0,(count+1) * sizeof(int));

    //统计各连通域白点个数

    for (int i = 0; i <nheight ;++i)

    {

        for (int j = 0 ; j<nwidth ;++j)

        {

            int base =*(mark + i * nwidth + j ) ;

            if (base !=0)

            {

                acc[base]++;

            }

        }

    }

 

    //删除小于area的连通域

    for (int i=0;i<nheight ;++i)

    {

        for (int j = 0 ; j < nwidth ; ++j)

        {

            int base = *(mark + i * nwidth + j );

            if (base >0 && acc[base] <area)

            {

                *(img + i * nwidth + j) = 0;

            }

        }

    }

    free(acc);

}

通过 Wiz 发布