1. 程式人生 > >OPENCV去除小連通區域,去除孔洞

OPENCV去除小連通區域,去除孔洞

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