samples/cpp/tutorial_code/ImgTrans/houghcircles.cpp

使用霍夫圆检测器的示例

 
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
 
using namespace cv;
using namespace std;
 
int main(int argc, char** argv)
{
    const char* filename = argc >=2 ? argv[1] : "smarties.png";
 
    // 加载图像
    Mat src = imread( samples::findFile( filename ), IMREAD_COLOR );
 
    // 检查图像是否加载成功
    if(src.empty()){
printf(" 错误打开图像\n");
printf(" 程序参数: [image_name -- 默认为 %s] \n", filename);
        return EXIT_FAILURE;
    }
 
    Mat gray;
cvtColor(src, gray, COLOR_BGR2GRAY);
 
medianBlur(gray, gray, 5);
 
vector<Vec3f> circles;
HoughCircles(gray, circles, HOUGH_GRADIENT, 1,
gray.rows/16, // 更改此值以检测彼此距离不同的圆
100, 30, 1, 30 // 更改最后两个参数
            // (min_radius & max_radius) 以检测更大的圆
    );
 
    for( size_t i = 0; i < circles.size(); i++ )
    {
        Vec3i c = circles[i];
        Point center = Point(c[0], c[1]);
        // 圆心
circle( src, center, 1, Scalar(0,100,100), 3, LINE_AA);
        // 圆轮廓
        int radius = c[2];
circle( src, center, radius, Scalar(255,0,255), 3, LINE_AA);
    }
 
imshow("detected circles", src);
cv::Mat::empty
 
    return EXIT_SUCCESS;
}