OPENCV去除小连通区域,去除孔洞的实例讲解

时间:2022-04-25 08:45:32

一、对于二值图,0代表黑色,255代表白色。去除小连通区域与孔洞,小连通区域用8邻域,孔洞用4邻域。

OPENCV去除小连通区域,去除孔洞的实例讲解

函数名字为:void RemoveSmallRegion(Mat &Src, Mat &Dst,int AreaLimit, int CheckMode, int NeihborMode)

CheckMode: 0代表去除黑区域,1代表去除白区域; NeihborMode:0代表4邻域,1代表8邻域;

如果去除小连通区域CheckMode=1,NeihborMode=1去除孔洞CheckMode=0,NeihborMode=0

记录每个像素点检验状态的标签,0代表未检查,1代表正在检查,2代表检查不合格(需要反转颜色),3代表检查合格或不需检查 。

1.先对整个图像扫描,如果是去除小连通区域,则将黑色的背景图作为合格,像素值标记为3,如果是去除孔洞,则将白色的色素点作为合格,像素值标记为3。

2.扫面整个图像,对图像进行处理。

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void RemoveSmallRegion(Mat &Src, Mat &Dst,int AreaLimit, int CheckMode, int NeihborMode)
{
    int RemoveCount = 0;
    //新建一幅标签图像初始化为0像素点,为了记录每个像素点检验状态的标签,0代表未检查,1代表正在检查,2代表检查不合格(需要反转颜色),3代表检查合格或不需检查
    //初始化的图像全部为0,未检查
    Mat PointLabel = Mat::zeros(Src.size(), CV_8UC1);
    if (CheckMode == 1)//去除小连通区域的白色点
    {
        cout << "去除小连通域.";
        for (int i = 0; i < Src.rows; i++)
        {
            for (int j = 0; j < Src.cols; j++)
            {
                if (Src.at<uchar>(i, j) < 10)
                {
                    PointLabel.at<uchar>(i, j) = 3;//将背景黑色点标记为合格,像素为3
                }
            }
        }
    }
    else//去除孔洞,黑色点像素
    {
        cout << "去除孔洞";
        for (int i = 0; i < Src.rows; i++)
        {
            for (int j = 0; j < Src.cols; j++)
            {
                if (Src.at<uchar>(i, j) > 10)
                {
                    PointLabel.at<uchar>(i, j) = 3;//如果原图是白色区域,标记为合格,像素为3
                }
            }
        }
    }
 
 
    vector<Point2i>NeihborPos;//将邻域压进容器
    NeihborPos.push_back(Point2i(-1, 0));
    NeihborPos.push_back(Point2i(1, 0));
    NeihborPos.push_back(Point2i(0, -1));
    NeihborPos.push_back(Point2i(0, 1));
    if (NeihborMode == 1)
    {
        cout << "Neighbor mode: 8邻域." << endl;
        NeihborPos.push_back(Point2i(-1, -1));
        NeihborPos.push_back(Point2i(-1, 1));
        NeihborPos.push_back(Point2i(1, -1));
        NeihborPos.push_back(Point2i(1, 1));
    }
    else cout << "Neighbor mode: 4邻域." << endl;
    int NeihborCount = 4 + 4 * NeihborMode;
    int CurrX = 0, CurrY = 0;
    //开始检测
    for (int i = 0; i < Src.rows; i++)
    {
        for (int j = 0; j < Src.cols; j++)
        {
            if (PointLabel.at<uchar>(i, j) == 0)//标签图像像素点为0,表示还未检查的不合格点
            { //开始检查
                vector<Point2i>GrowBuffer;//记录检查像素点的个数
                GrowBuffer.push_back(Point2i(j, i));
                PointLabel.at<uchar>(i, j) = 1;//标记为正在检查
                int CheckResult = 0;
 
 
                for (int z = 0; z < GrowBuffer.size(); z++)
                {
                    for (int q = 0; q < NeihborCount; q++)
                    {
                        CurrX = GrowBuffer.at(z).x + NeihborPos.at(q).x;
                        CurrY = GrowBuffer.at(z).y + NeihborPos.at(q).y;
                        if (CurrX >= 0 && CurrX<Src.cols&&CurrY >= 0 && CurrY<Src.rows) //防止越界
                        {
                            if (PointLabel.at<uchar>(CurrY, CurrX) == 0)
                            {
                                GrowBuffer.push_back(Point2i(CurrX, CurrY)); //邻域点加入buffer
                                PointLabel.at<uchar>(CurrY, CurrX) = 1;   //更新邻域点的检查标签,避免重复检查
                            }
                        }
                    }
                }
                if (GrowBuffer.size()>AreaLimit) //判断结果(是否超出限定的大小),1为未超出,2为超出
                    CheckResult = 2;
                else
                {
                    CheckResult = 1;
                    RemoveCount++;//记录有多少区域被去除
                }
 
 
                for (int z = 0; z < GrowBuffer.size(); z++)
                {
                    CurrX = GrowBuffer.at(z).x;
                    CurrY = GrowBuffer.at(z).y;
                    PointLabel.at<uchar>(CurrY,CurrX)+=CheckResult;//标记不合格的像素点,像素值为2
                }
                //********结束该点处的检查**********
 
 
            }
        }
 
 
    }
 
 
    CheckMode = 255 * (1 - CheckMode);
    //开始反转面积过小的区域
    for (int i = 0; i < Src.rows; ++i)
    {
        for (int j = 0; j < Src.cols; ++j)
        {
            if (PointLabel.at<uchar>(i,j)==2)
            {
                Dst.at<uchar>(i, j) = CheckMode;
            }
            else if (PointLabel.at<uchar>(i, j) == 3)
            {
                Dst.at<uchar>(i, j) = Src.at<uchar>(i, j);
                
            }
        }
    }
    cout << RemoveCount << " objects removed." << endl;
}

调用函数:dst是原来的二值图。

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Mat erzhi1 = Mat::zeros(srcImage.rows, srcImage.cols, CV_8UC1);
RemoveSmallRegion(dst, erzhi,100, 1, 1);
RemoveSmallRegion(erzhi, erzhi,100, 0, 0);
imshow("erzhi1", erzhi);

OPENCV去除小连通区域,去除孔洞的实例讲解

和之前的图像相比

OPENCV去除小连通区域,去除孔洞的实例讲解

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原文链接:https://blog.csdn.net/dajiyi1998/article/details/60601410