学习c++版opencv3.4之21-霍夫直线检测

霍夫变换用来直线，圆等检测，使用的前提条件是边缘检测（如canny，sobel等）已经完成。

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

using namespace std;
using namespace cv;

Mat src, dst;
int main(){
    Mat src1;
    src1 = imread("/Users/ming/Documents/test2.jpg");
    resize(src1, src, Size(src1.cols/2, src1.rows/2));
    if (!src.data){
        printf("cannot load image ...");
        return -1;
    }
    namedWindow("src img", CV_WINDOW_AUTOSIZE);
    imshow("src img", src);
    Mat src_gray;
    cvtColor(src, src_gray, CV_WINDOW_AUTOSIZE);
    Mat src_canny;
    Canny(src_gray, src_canny, 120, 200); //边缘检测
    imshow("edge img", src_canny);
    
    //霍夫直线检测
    vector<Vec4f> line_data;
    HoughLinesP(src_canny, line_data, 1, CV_PI/180.0, 80, 10 ,20);
    //把得到的直线显示在图中
    Scalar color = Scalar(255, 0, 0);
    for (size_t i = 0; i < line_data.size(); i++){
        Vec4f temp = line_data[i];
        line(src, Point(temp[0], temp[1]), Point(temp[2], temp[3]), color, 2);
    }
    imshow("houghLinesP img", src);

    waitKey(0);
    return 0;
}