opencvsharp 编写canny高精度亚像素分块多线程找圆心，请编写c#函数

以下是一个使用OpenCvSharp实现的Canny边缘检测和Hough圆检测的示例代码，其中使用了多线程：

using System.Collections.Generic;
using System.Threading.Tasks;
using OpenCvSharp;

public static class CircleDetector
{
    public static List<CircleSegment> FindCircles(Mat image, double cannyThreshold = 100, double minRadius = 0, double maxRadius = 0)
    {
        var grayImage = new Mat();
        Cv2.CvtColor(image, grayImage, ColorConversionCodes.BGR2GRAY);

        var edges = new Mat();
        Cv2.Canny(grayImage, edges, cannyThreshold, cannyThreshold * 3);

        var circles = new List<CircleSegment>();
        var lines = new Mat();
        Cv2.HoughCircles(edges, circles, HoughModes.Gradient, 1, image.Rows / 8.0, cannyThreshold, 30, (int)minRadius, (int)maxRadius);

        return circles;
    }

    public static List<CircleSegment> FindCirclesMultiThreaded(Mat image, double cannyThreshold = 100, double minRadius = 0, double maxRadius = 0, int numThreads = 4)
    {
        var grayImage = new Mat();
        Cv2.CvtColor(image, grayImage, ColorConversionCodes.BGR2GRAY);

        var edges = new Mat();
        Cv2.Canny(grayImage, edges, cannyThreshold, cannyThreshold * 3);

        var circles = new List<CircleSegment>();
        var lines = new Mat();

        Parallel.For(0, numThreads, threadNum =>
        {
            var startRow = threadNum * (image.Rows / numThreads);
            var endRow = (threadNum + 1) * (image.Rows / numThreads);

            var threadCircles = new List<CircleSegment>();
            Cv2.HoughCircles(edges[startRow, endRow, 0, image.Cols], threadCircles, HoughModes.Gradient, 1, (endRow - startRow) / 8.0, cannyThreshold, 30, (int)minRadius, (int)maxRadius);

            lock (circles)
            {
                circles.AddRange(threadCircles);
            }
        });

        return circles;
    }
}

这个函数接受一个OpenCvSharp的Mat对象作为输入图像，并返回一个CircleSegment的列表，每个CircleSegment表示检测到的圆的位置和半径。可以通过调整参数来控制Canny边缘检测和Hough圆检测算法的灵敏度和准确度。如果您需要更高的精度，可以尝试使用更小的minRadius和maxRadius参数，但这可能会增加计算时间。