OpenCV笔记（十）

霍夫变换用于直线检测：

#include<opencv2/opencv.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<iostream>
using namespace cv;
using namespace std;
int main(){
	Mat srcImage=imread("line.jpg",1);
	Mat dstImage1,dstImage2;
	Canny(srcImage,dstImage1,150,200,3);
	imshow("1",dstImage1);
	cvtColor(dstImage1,dstImage2,CV_GRAY2BGR);
	vector<Vec2f>lines;
	HoughLines(dstImage1,lines,1,CV_PI/180,120,0,0);
	for(size_t i=0;i<lines.size();i++){
		float rho=lines[i][0],theta=lines[i][1];
		Point pt1,pt2;
		double a=cos(theta),b=sin(theta);
		double x0=a*rho,y0=b*rho;
		int N=500;
		pt1.x=cvRound(x0+N*(-b));
		pt2.y=cvRound(y0+N*(a));
		pt2.x=cvRound(x0-N*(-b));
		pt2.y=cvRound(y0-N*(a));
		line(dstImage2,pt1,pt2,Scalar(0,255,0),1,CV_AA);
	}
	imshow("11",dstImage2);
	waitKey(0);
}

圆形检测：

#include<opencv2/opencv.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<iostream>
using namespace cv;
using namespace std;
int main(){
	Mat srcImage=imread("circle.jpg",1);
	imshow("0",srcImage);
	vector<Vec3f>circles;
	Mat grayImage;
	cvtColor(srcImage,grayImage,CV_BGR2GRAY);
	HoughCircles(grayImage,circles,CV_HOUGH_GRADIENT,1,10,200,44,0,0);
	for(size_t i=0;i<circles.size();i++){
		Point center(cvRound(circles[i][0]),cvRound(circles[i][1]));
		int radius=cvRound(circles[i][2]);
		circle(srcImage,center,radius,Scalar(0,0,255),4);
	}
	imshow("1",srcImage);
	waitKey(0);
}