用OpenCVSharp 4.5 跑一遍 OpenCV官方教程
原官方教程链接:OpenCV: Image Moments
核心函数:
using System;
using OpenCvSharp;
namespace ConsoleApp1
{
class tutorial27 : ITutorial
{
static Mat src_gray = new Mat();
static int thresh = 100;
static RNG rng = new RNG(12345);
public void Run()
{
Mat src = Cv2.ImRead("I:\\csharp\\images\\cartoons.jpg");
if (src.Empty())
{
Console.WriteLine("Could not open or find the image!");
return;
}
Cv2.CvtColor(src, src_gray, ColorConversionCodes.BGR2GRAY);
Cv2.Blur(src_gray, src_gray, new Size(5, 5));
Cv2.NamedWindow("Source", WindowFlags.AutoSize);
Cv2.ImShow("Source", src);
Cv2.CreateTrackbar("Canny thresh:", "Source", ref thresh, 255, thresh_callback);
thresh_callback(0, IntPtr.Zero);
Cv2.WaitKey();
}
private void thresh_callback(int pos, IntPtr userData)
{
Mat canny_output = new Mat();
Cv2.Canny(src_gray, canny_output, thresh, thresh * 2);
Point[][] contours;
HierarchyIndex[] hIndex;
Cv2.FindContours(canny_output, out contours, out hIndex, RetrievalModes.Tree, ContourApproximationModes.ApproxSimple);
Moments[] mu = new Moments[contours.Length];
for (int i = 0; i < contours.Length; i++)
{
mu[i] = Cv2.Moments(contours[i]);
}
Point2f[] mc = new Point2f[contours.Length];
for (int i = 0; i < contours.Length; i++)
{
//add 1e-5 to avoid division by zero
mc[i] = new Point2f((float)(mu[i].M10 / (mu[i].M00 + 1e-5)),
(float)(mu[i].M01 / (mu[i].M00 + 1e-5)));
Console.WriteLine("mc[{0}]={1}", i, mc[i]);
}
Mat drawing = Mat.Zeros(canny_output.Size(), MatType.CV_8UC3);
for (int i = 0; i < contours.Length; i++)
{
Scalar color = new Scalar(rng.Uniform(0, 256), rng.Uniform(0, 256), rng.Uniform(0, 256));
Cv2.DrawContours(drawing, contours, (int)i, color, 1);
Cv2.Circle(drawing, (Point)mc[i], 4, color, 1);
}
Cv2.ImShow("Contours", drawing);
Console.WriteLine("\t Info: Area and Contour Length");
for (int i = 0; i < contours.Length; i++)
{
Console.WriteLine(" * Contour[{0}] - Area (M_00) = {1} - Area OpenCV:{2:0.###} - Length:{3:0.###} ",
i, mu[i].M00,
Cv2.ContourArea(contours[i]),
Cv2.ArcLength(contours[i], true)
);
}
}
}
}