EmguCV环境配置：

​​​​​​Emgu CV4图像处理之环境搭建1(C#)_emgucv 4.7-CSDN博客

本文测试环境：

win10  64位

vistual studio 2019  

Emgu CV 4.6.0

环境配置准备：

1 新增控制台项目，.net framework为4.7.2

2  把win-x64目录的native目录下的文件全部拷贝到项目的运行目录Debug目录下

3  项目选择x64

4 添加项目引用Emgu.CV.dll、Emgu.CV.Platform.NetFramework.dll、System.Drawing.dll和System.Runtime.InteropServices.RuntimeInformation.dll  

代码如下：

static void ReadMultiBarCode3(string imageFileName)
{
    Emgu.CV.Mat mat = Emgu.CV.CvInvoke.Imread(imageFileName);
    Mat gray_srvPic = new Mat();
    Emgu.CV.CvInvoke.CvtColor(mat, gray_srvPic, Emgu.CV.CvEnum.ColorConversion.Bgr2Gray);
    //compute the Scharr gradient magnitude representation of the images
    //in both the x and y direction using OpenCV 2.4
    IOutputArray dstX = new Mat();
    IOutputArray dstY = new Mat();
    Emgu.CV.CvInvoke.Sobel(gray_srvPic, dstX, DepthType.Cv32F, 1, 0, -1);
    Emgu.CV.CvInvoke.Sobel(gray_srvPic, dstY, DepthType.Cv32F, 0, 1, -1);
    
    //subtract the y-gradient from the x-gradient
    IOutputArray gradient = new Mat();
    Emgu.CV.CvInvoke.Subtract(dstX, dstY, gradient);
    
    Emgu.CV.CvInvoke.ConvertScaleAbs(gradient, gradient,1,0);
    IOutputArray gradientDst1 = new Mat();
    Emgu.CV.CvInvoke.Blur(gradient, gradientDst1, new Size(9, 9),new Point(-1,-1));
    IOutputArray gradientDst2 = new Mat();
    Emgu.CV.CvInvoke.Threshold(gradientDst1, gradientDst2, 100, 255, ThresholdType.Binary);

    IOutputArray kernel = new Mat();
    kernel=Emgu.CV.CvInvoke.GetStructuringElement(ElementShape.Rectangle, new Size(3, 3), new Point(-1,-1));
    IInputOutputArray closed = new Mat();
    //closed = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel)
    Emgu.CV.CvInvoke.MorphologyEx(gradientDst2, closed, MorphOp.Close, kernel, new Point(-1,-1), 1, BorderType.Default, new MCvScalar());


    //# perform a series of erosions and dilations
    //closed = cv2.erode(closed, None, iterations = 4)
    Emgu.CV.CvInvoke.Erode(closed, closed, null, new Point(-1, -1), 1, BorderType.Default, new MCvScalar());

    //closed = cv2.dilate(closed, None, iterations = 4)
    Emgu.CV.CvInvoke.Dilate(closed, closed, null, new Point(-1, -1), 1, BorderType.Default, new MCvScalar());

    //Mat element = CvInvoke.GetStructuringElement(Emgu.CV.CvEnum.ElementShape.Rectangle, new Size(3, 3), new Point(-1, -1));
    //CvInvoke.Dilate(closed, closed, element, new Point(-1, -1), 4, Emgu.CV.CvEnum.BorderType.Default, new MCvScalar());

    //cnts = cv2.findContours(closed.copy(), cv2.RETR_EXTERNAL,
    //                        cv2.CHAIN_APPROX_SIMPLE)
    IOutputArray output1 = new Mat();
    VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint();
    VectorOfRect hierarchy = new VectorOfRect();
    //查找轮廓
    CvInvoke.FindContours(closed, contours, hierarchy, Emgu.CV.CvEnum.RetrType.External, Emgu.CV.CvEnum.ChainApproxMethod.ChainApproxSimple);


    

    CvInvoke.Polylines(mat, contours, true, new MCvScalar(0, 255, 0), 5);

    CvInvoke.Imshow("after_pic", mat);

    CvInvoke.WaitKey(0);
}

主程序测试：

static void Main(string[] args)
{
    ReadMultiBarCode3("test.png");
    Console.ReadLine();
}

test.png图片如下：

运行结果如下：