HoughCircles()圆检测的正确阈值opencv c++

#include <opencv2/opencv.hpp>
#include <iostream>

int main() {
    cv::Mat src = cv::imread("circles.jpg", cv::IMREAD_COLOR);
    if (src.empty()) {
        std::cout << "Could not open or find the image!" << std::endl;
        return -1;
    }

    cv::Mat gray;
    cv::cvtColor(src, gray, cv::COLOR_BGR2GRAY);
    cv::GaussianBlur(gray, gray, cv::Size(9, 9), 2, 2);

    std::vector<cv::Vec3f> circles;
    cv::HoughCircles(gray, circles, cv::HOUGH_GRADIENT, 1, gray.rows / 8, 200, 100, 0, 0);

    for (size_t i = 0; i < circles.size(); i++) {
        cv::Point center(cvRound(circles[i][0]), cvRound(circles[i][1]));
        int radius = cvRound(circles[i][2]);
        cv::circle(src, center, 3, cv::Scalar(0, 255, 0), -1, 8, 0); // center
        cv::circle(src, center, radius, cv::Scalar(0, 0, 255), 3, 8, 0); // border
    }

    cv::imshow("Detected Circles", src);
    cv::waitKey(0);
    return 0;
}