去除小面积(注：输出图像需要初始化，否则会报错)

/*
参数说明：1.输入图像，
2.输出图像(去除掉指定小面积后的图像)，
3.需要去除的面积，
4.去除方式(==1去除小连通区域的白色点，==0去除孔洞，黑色点像素)
5.邻域方式：NeihborMode == 1八邻域，NeihborMode == 0四邻域
*/
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;
}