Line detection image processing using C#

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C#

.NET

WinForms

Emgu-CV

, +

Hello,
here i am working on C# WinForms desktop application where i have to do some image processing on the images. there is the lines between an object that showing in the image.
here i am adding some reference images in links.
image1
image2
image3
image4
image5
image6

What I have tried:

i am doing some image processing using EmguCV library for C#. i have not getting the output i want and it supposed to be.
here are some images of output i am getting.

see all the output images. there are in many images are not detecting the lines on the object and some images are get line but half. i want to detect whole black line on the object are. if there's black line of 40px then the draw line at least 90% on the detected black line.

output1
output2
output3
output4
output5


the code i have tried is given below.

if (img_path != null)
           {

               try
               {
                   Image<Bgr, byte> imgInput = new Image<Bgr, byte>(img_path);
                   // Convert the image to grayscale
                   Image<Gray, byte> gray = imgInput.Convert<Gray, byte>();

                   // Apply a threshold
                   gray = gray.ThresholdBinary(new Gray(100), new Gray(255));

                   // Detect edges
                   Image<Gray, byte> edges = gray.Canny(100, 50);

                   // Find contours
                   VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint();
                   Mat hierarchy = new Mat();
                   CvInvoke.FindContours(edges, contours, hierarchy, RetrType.List, ChainApproxMethod.ChainApproxSimple);

                   // Filter the contours
                   List<VectorOfPoint> filteredContours = new List<VectorOfPoint>();
                   for (int i = 0; i < contours.Size; i++)
                   {
                       VectorOfPoint contour = contours[i];
                       double area = CvInvoke.ContourArea(contour);
                       if (area > 500 && area < 10000) // adjust these values based on your image
                       {
                           filteredContours.Add(contour);
                       }
                   }

                   // Detect lines
                   LineSegment2D[] lines = CvInvoke.HoughLinesP(
                       edges, // input image
                       1, // rho
                       Math.PI / 180, // theta
                       100, // threshold
                       3, // minLineLength
                       10 // maxLineGap
                   );

                   // Draw the lines
                   foreach (LineSegment2D line in lines)
                   {
                       imgInput.Draw(line, new Bgr(Color.Red), 2);
                   }



                   // Display the result
                   pictureBox2.Image = imgInput.ToBitmap();

               }
               catch (Exception ex)
               {
                   MessageBox.Show(ex.Message);
               }
           }