opencv学习笔记5 霍夫变换漫水填充

比眉伴天荒 2023-06-04 03:54 13阅读 0赞

## 一。霍夫线变换 ##

### 1.标准霍夫变换（StandardHough Transform，SHT），由HoughLines函数调用。 ###

### 2.多尺度霍夫变换（Multi-ScaleHough Transform，MSHT），由HoughLines函数调用。 ###

void HoughLines(InputArray image, OutputArray lines, double rho, double theta, int threshold, double srn=0, double stn=0 )

![1615707-20190912094840854-2007910666.png][]

1 #include<opencv.hpp>
     2 #include<vector>
     3 using namespace std;
     4 using namespace cv;
     5 int main()
     6 {
     7     Mat src = imread("E:/house.png");
     8     Mat gray,dst;
     9     Canny(src, gray, 50, 200);
    10     cvtColor(gray, dst, CV_GRAY2BGR);
    11     vector<Vec2f> lines; //Vec2f存放2个float的向量 vector<Vec2f>类似二维数组
    12     HoughLines(gray, lines, 1, CV_PI / 180, 160, 0, 0); //对二值图像进行霍夫变换，保存直线信息于lines
    13     for (size_t i = 0; i < lines.size(); i++)
    14     {
    15         float rho = lines[i][0], theta = lines[i][1]; //rho为原点到直线的最短距离r，theta为距离的角度θ
    16         Point pt1, pt2;
    17         double a = cos(theta), b = sin(theta);
    18         double x0 = a * rho, y0 = b * rho;  //x=rcosθ，y=rsinθ
    19         pt1.x = cvRound(x0 + 1000 * (-b));
    20         pt1.y = cvRound(y0 + 1000 * (a));
    21         pt2.x = cvRound(x0 - 1000 * (-b));
    22         pt2.y = cvRound(y0 - 1000 * (a));
    23         line(dst, pt1, pt2, Scalar(55, 100, 195), 1, CV_AA);
    24     }
    25     imshow("src", src);
    26     imshow("dst,",dst);
    27     waitKey();
    28     return 0;
    29 }

![1615707-20190912105334245-943263674.png][]

### 3.累计概率霍夫变换（ProgressiveProbabilistic Hough Transform，PPHT），由HoughLinesP函数调用。 ###

void HoughLinesP(InputArray image, OutputArray lines, double rho, double theta, int threshold, double minLineLength=0, double maxLineGap=0 )

![1615707-20190912105726369-1500879253.png][]

1 #include<opencv.hpp>
     2 #include<vector>
     3 using namespace std;
     4 using namespace cv;
     5 int main()
     6 {
     7     Mat src = imread("E:/house.png");
     8     Mat gray, dst;
     9     Canny(src, gray, 50, 200);
    10     cvtColor(gray, dst, CV_GRAY2BGR);
    11     vector<Vec4i> lines; 
    12     HoughLinesP(gray, lines, 1, CV_PI / 180, 50, 50, 10);
    13     for (size_t i = 0; i < lines.size(); i++)
    14     {
    15         Vec4i l = lines[i];
    16         line(dst, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(200, 150, 30), 1, 8);
    17     }
    18     imshow("src", src);
    19     imshow("dst,", dst);
    20     waitKey();
    21     return 0;
    22 }

![1615707-20190912110544034-1986215562.png][]

## 二。霍夫圆变换 ##

void HoughCircles(InputArray image,OutputArray circles, int method, double dp, double minDist, double param1=100,double param2=100, int minRadius=0, int maxRadius=0 )  
![1615707-20190912110909277-1290309322.png][]

1 #include<opencv.hpp>
     2 #include<vector>
     3 using namespace std;
     4 using namespace cv;
     5 int main()
     6 {
     7     Mat src = imread("E:/circle.png");
     8     Mat gray, blur;
     9     cvtColor(src, gray, CV_BGR2GRAY);
    10     GaussianBlur(gray, blur, Size(9, 9), 2, 2);
    11     vector<Vec3f>Circles;
    12     HoughCircles(blur, Circles, CV_HOUGH_GRADIENT, 1, 10, 200, 50, 0, 0);
    13     for (size_t i = 0; i < Circles.size(); i++)
    14     {
    15         Point center(cvRound(Circles[i][0]), cvRound(Circles[i][1]));
    16         int radius = cvRound(Circles[i][2]);
    17         //绘制圆轮廓
    18         circle(src, center, radius,Scalar(0,0,255),3,8);
    19     }
    20     imshow("src", src);
    21     waitKey();
    22     return 0;
    23 }

![1615707-20190912112915891-412885981.png][]

## 三。漫水填充 ##

### 1.带mask版本 ###

int floodFill(InputOutputArray image, InputOutputArray mask, Point seedPoint,Scalar newVal, Rect\* rect=0, Scalar loDiff=Scalar(), Scalar upDiff=Scalar(), int flags=4 )

### 2.不带mask版本 ###

int floodFill(InputOutputArray image, Point seedPoint, Scalar newVal, Rect\* rect=0, Scalar loDiff=Scalar(), Scalar upDiff=Scalar(), int flags=4 )  
![1615707-20190912115440204-1341166249.png][]

1     Mat src = imread("E:/test.jpg");
    2     imshow("src", src);
    3     Rect rect;
    4     floodFill(src, Point(50, 50), Scalar(255, 255, 255), &rect,Scalar(20, 20, 20), Scalar(20, 20, 20));
    5     imshow("dst", src);
    6     waitKey();
    7     return 0;

![1615707-20190912131610518-422587105.png][]

参考：[https://blog.csdn.net/poem\_qianmo/article/details/28261997][https_blog.csdn.net_poem_qianmo_article_details_28261997]

转载于:https://www.cnblogs.com/sclu/p/11510997.html

[1615707-20190912094840854-2007910666.png]: /images/20230601/9882a970a36643689851930a67e5b899.png
[1615707-20190912105334245-943263674.png]: /images/20230601/56c2950bb5754badb4215bcdfe5fb294.png
[1615707-20190912105726369-1500879253.png]: /images/20230601/f955ef941e2b415eb5cefb9488dd5f59.png
[1615707-20190912110544034-1986215562.png]: /images/20230601/d9a929e6e4064c409885e4d9ecd64123.png
[1615707-20190912110909277-1290309322.png]: /images/20230601/c7d7a8e1f3274d17804601b99c77b1e1.png
[1615707-20190912112915891-412885981.png]: /images/20230601/d2c2d2bfef5e4f9d8d546c7307c272f4.png
[1615707-20190912115440204-1341166249.png]: /images/20230601/060636acafc54e24931ed72acb5d454a.png
[1615707-20190912131610518-422587105.png]: /images/20230601/b15845169fa84a1b99a44ad9f6218755.png
[https_blog.csdn.net_poem_qianmo_article_details_28261997]: https://blog.csdn.net/poem_qianmo/article/details/28261997