简单应用：

代码：

#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>
using namespace std;
using namespace cv;

int main() 
{
	Mat img_gray, img_two, img_canny;
	Mat img = imread("D:/C++/huofu.jpg");
	cvtColor(img,img_gray,COLOR_BGR2GRAY);
	threshold(img_gray,img_two,100,255,THRESH_OTSU);

	Canny(img_two,img_canny,30,90,3,false);

	vector<Vec2f>lines;
	HoughLines(img_canny,lines,1,CV_PI/180,125,0,0);

	vector<Vec2f>::iterator it = lines.begin();
	for ( ;it!= lines.end(); it++) 
	{
		float rho = (*it)[0], theta = (*it)[1];
		Point pt1, pt2;
		double a = cos(theta), b = sin(theta);
		double x0 = a * rho, y0 = b * rho;

		pt1.x = saturate_cast<int>(x0+1000*(-b));
		pt1.y = saturate_cast<int>(y0 + 1000 * (a));
		pt2.x = saturate_cast<int>(x0 + 1000 * (-b));
		pt2.y = saturate_cast<int>(y0 + 1000 * (a));

		line(img,pt1,pt2,Scalar(0,255,255),1,LINE_AA);


	}

	imshow("img",img);
	imshow("img_canny",img_canny);
	waitKey(0);
	return 0;
}

效果：

 进阶：

代码：

#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>
using namespace std;
using namespace cv;

int main()
{
	Mat img_gray, img_two, img_canny;
	Mat img = imread("D:/C++/huofu.jpg");
	cvtColor(img, img_gray, COLOR_BGR2GRAY);
	threshold(img_gray, img_two, 100, 255, THRESH_OTSU);

	Canny(img_two, img_canny, 30, 90, 3, false);

	vector<Vec4i>lines;
	HoughLinesP(img_canny, lines, 1, CV_PI / 180, 6, 0, 0);

	
	for (size_t i=0; i< lines.size(); ++i)
	{
		int x1 = lines[0][0];
		int y1 = lines[0][1];
		int x2 = lines[0][2];
		int y2 = lines[0][3];

		Vec4i line_ = lines[i];
		line(img, Point(line_[0],line_[1]), Point(line_[2], line_[3]), Scalar(0, 255, 255), 2, LINE_AA);


	}

	imshow("img", img);
	imshow("img_canny", img_canny);
	waitKey(0);
	return 0;
}

效果：