OPENCV去除小連通區域,去除孔洞
阿新 • • 發佈:2019-01-07
一、對於二值圖,0代表黑色,255代表白色。去除小連通區域與孔洞,小連通區域用8鄰域,孔洞用4鄰域。
函式名字為:void RemoveSmallRegion(Mat &Src, Mat &Dst,int AreaLimit, int CheckMode, int NeihborMode)
CheckMode: 0代表去除黑區域,1代表去除白區域; NeihborMode:0代表4鄰域,1代表8鄰域;
如果去除小連通區域CheckMode=1,NeihborMode=1去除孔洞CheckMode=0,NeihborMode=0
記錄每個畫素點檢驗狀態的標籤,0代表未檢查,1代表正在檢查,2代表檢查不合格(需要反轉顏色),3代表檢查合格或不需檢查 。
1.先對整個影象掃描,如果是去除小連通區域,則將黑色的背景圖作為合格,畫素值標記為3,如果是去除孔洞,則將白色的色素點作為合格,畫素值標記為3。
2.掃面整個影象,對影象進行處理。
void RemoveSmallRegion(Mat &Src, Mat &Dst,int AreaLimit, int CheckMode, int NeihborMode) { int RemoveCount = 0; //新建一幅標籤影象初始化為0畫素點,為了記錄每個畫素點檢驗狀態的標籤,0代表未檢查,1代表正在檢查,2代表檢查不合格(需要反轉顏色),3代表檢查合格或不需檢查 //初始化的影象全部為0,未檢查 Mat PointLabel = Mat::zeros(Src.size(), CV_8UC1); if (CheckMode == 1)//去除小連通區域的白色點 { cout << "去除小連通域."; 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;//將背景黑色點標記為合格,畫素為3 } } } } else//去除孔洞,黑色點畫素 { 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;//如果原圖是白色區域,標記為合格,畫素為3 } } } } vector<Point2i>NeihborPos;//將鄰域壓進容器 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鄰域." << 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鄰域." << endl; int NeihborCount = 4 + 4 * NeihborMode; int CurrX = 0, CurrY = 0; //開始檢測 for (int i = 0; i < Src.rows; i++) { for (int j = 0; j < Src.cols; j++) { if (PointLabel.at<uchar>(i, j) == 0)//標籤影象畫素點為0,表示還未檢查的不合格點 { //開始檢查 vector<Point2i>GrowBuffer;//記錄檢查畫素點的個數 GrowBuffer.push_back(Point2i(j, i)); PointLabel.at<uchar>(i, j) = 1;//標記為正在檢查 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)); //鄰域點加入buffer PointLabel.at<uchar>(CurrY, CurrX) = 1; //更新鄰域點的檢查標籤,避免重複檢查 } } } } if (GrowBuffer.size()>AreaLimit) //判斷結果(是否超出限定的大小),1為未超出,2為超出 CheckResult = 2; else { CheckResult = 1; RemoveCount++;//記錄有多少區域被去除 } for (int z = 0; z < GrowBuffer.size(); z++) { CurrX = GrowBuffer.at(z).x; CurrY = GrowBuffer.at(z).y; PointLabel.at<uchar>(CurrY,CurrX)+=CheckResult;//標記不合格的畫素點,畫素值為2 } //********結束該點處的檢查********** } } } CheckMode = 255 * (1 - CheckMode); //開始反轉面積過小的區域 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; }
呼叫函式:dst是原來的二值圖。
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);
和之前的影象相比