【练习6.8】霍夫直线变换、圆变换，cvCanny边缘检测，找圆找直线

 

提纲

题目要求

程序代码

结果图片

要言妙道

 

 

 

  

 

题目要求：

 使用霍夫直线变换和霍夫圆变换

a、找圆

b、找直线

 

程序代码：

  1 // OpenCVExerciseTesting.cpp : 定义控制台应用程序的入口点。
  2 //
  3 //D:\\Work\\Work_Programming\\Source\\Image\\lena.jpg
  4 
  5 
  6 #include "stdafx.h"
  7 #include <cv.h>
  8 #include <highgui.h>
  9 #include <iostream>
 10 
 11 #include <opencv2/legacy/legacy.hpp>
 12 //#pragma comment(lib, "opencv_legacy2411.lib")
 13 
 14 using namespace cv;
 15 using namespace std;
 16 
 17 //函数声明-->--->-->--->-->--->-->--->//
 18 
 19 
 20 //<--<--<--<--<--<--<--<--<--函数声明//
 21 
 22 int _tmain(int argc, _TCHAR* argv[])
 23 {
 24     char * soutceFile = "D:\\Work\\Work_Programming\\Source\\Image\\OpenCVExerciseImage\\第6章\\奥运五环2.jpg";
 25     IplImage * image_Resource = cvLoadImage(soutceFile, CV_LOAD_IMAGE_GRAYSCALE);
 26     assert(image_Resource);
 27 
 28     cvNamedWindow("原始图像", CV_WINDOW_AUTOSIZE);
 29     cvNamedWindow("题目_a", CV_WINDOW_AUTOSIZE);
 30     cvNamedWindow("题目_b", CV_WINDOW_AUTOSIZE);
 31 
 32     cvShowImage("原始图像", image_Resource);
 33 
 34     //---------------------------a：开始--------------------------------//
 35 
 36     IplImage * image_Result_a = cvCloneImage(image_Resource);
 37     //cvZero(image_Result_a);
 38 
 39     CvMemStorage* storage = cvCreateMemStorage(0);
 40     CvSeq* results = cvHoughCircles(
 41         image_Result_a,
 42         storage,
 43         CV_HOUGH_GRADIENT,
 44         1,
 45         image_Result_a->width / 10,
 46         200
 47         );
 48 
 49     for (int i = 0; i < results->total; i++)
 50     {
 51         float* p = (float*)cvGetSeqElem(results, i);
 52         CvPoint pt = cvPoint(cvRound(p[0]), cvRound(p[1]));
 53         cvCircle(
 54             image_Result_a,
 55             pt,
 56             cvRound(p[2]),
 57             CV_RGB(0xff, 0xff, 0xff)
 58             );
 59     }
 60 
 61     cvShowImage("题目_a", image_Result_a);
 62 
 63     //---------------------------a：结束--------------------------------//    
 64 
 65     //---------------------------b：开始--------------------------------//
 66 
 67     soutceFile = "D:\\Work\\Work_Programming\\Source\\Image\\OpenCVExerciseImage\\第6章\\窗.jpg";
 68     image_Resource = cvLoadImage(soutceFile, CV_LOAD_IMAGE_UNCHANGED);
 69     assert(image_Resource);
 70 
 71     int i;
 72     IplImage* dst = cvCreateImage(cvGetSize(image_Resource), 8, 1);
 73     IplImage* color_dst = cvCreateImage(cvGetSize(image_Resource), 8, 3);
 74     CvMemStorage* storage2 = cvCreateMemStorage(0);
 75     CvSeq* lines = 0;
 76      
 77     IplImage* src1 = cvCreateImage(cvSize(image_Resource->width, image_Resource->height), IPL_DEPTH_8U, 1);
 78     cvCvtColor(image_Resource, src1, CV_BGR2GRAY);
 79     cvCanny(src1, dst, 50, 200, 3);
 80     cvCvtColor(dst, color_dst, CV_GRAY2BGR);
 81 
 82     lines = cvHoughLines2(dst, storage, CV_HOUGH_PROBABILISTIC, 1, CV_PI / 180, 80, 30, 10);
 83     for (i = 0; i < lines->total; i++)
 84     {
 85         CvPoint* line = (CvPoint*)cvGetSeqElem(lines, i);
 86         cvLine(color_dst, line[0], line[1], CV_RGB(255, 0, 0), 2, 8);
 87     }
 88 
 89     cvNamedWindow("Source", CV_WINDOW_NORMAL);
 90     cvShowImage("Source", image_Resource);
 91     cvNamedWindow("Hough", CV_WINDOW_NORMAL);
 92     cvShowImage("Hough", color_dst);
 93 
 94     //---------------------------b：结束--------------------------------//    
 95 
 96     cvWaitKey(0);
 97 
 98     cvReleaseImage(&image_Resource);
 99     cvReleaseImage(&image_Result_a);
100     //cvReleaseImage(&image_Result_b);
101 
102     cvDestroyAllWindows();
103 
104     return 0;
105 }

 

 优秀代码参考：

 1 #include <cv.h>
 2 #include <highgui.h>
 3 #include <math.h>
 4 int main(int argc, char** argv)
 5 {
 6 IplImage* img;
 7 if( argc == 2 && (img=cvLoadImage(argv[1], 1))!= 0)
 8 {
 9 IplImage* gray = cvCreateImage( cvGetSize(img), 8, 1 );
10 CvMemStorage* storage = cvCreateMemStorage(0);
11 cvCvtColor( img, gray, CV_BGR2GRAY );
12 cvSmooth( gray, gray, CV_GAUSSIAN, 9, 9 ); // smooth it, otherwise a lot of false circles may be
13 detected
14 CvSeq* circles = cvHoughCircles( gray, storage, CV_HOUGH_GRADIENT, 2, gray->height/4, 200, 100 );
15 int i;
16 for( i = 0; i < circles->total; i++ )
17 {
18 float* p = (float*)cvGetSeqElem( circles, i );
19 cvCircle( img, cvPoint(cvRound(p[0]),cvRound(p[1])), 3, CV_RGB(0,255,0), -1, 8, 0 );
20 cvCircle( img, cvPoint(cvRound(p[0]),cvRound(p[1])), cvRound(p[2]), CV_RGB(255,0,0), 3, 8, 0 );
21 }
22 cvNamedWindow( "circles", 1 );
23 cvShowImage( "circles", img );
24 }
25 return 0;
26 }

霍夫圆变换Example

 1 /* This is a standalone program. Pass an image name as a first parameter
 2 of the program.Switch between standard and probabilistic Hough transform
 3 by changing "#if 1" to "#if 0" and back */
 4 #include <cv.h>
 5 #include <highgui.h>
 6 #include <math.h>
 7 int main(int argc, char** argv)
 8 {
 9 IplImage* src;
10 if( argc == 2 && (src=cvLoadImage(argv[1], 0))!= 0)
11 {
12 IplImage* dst = cvCreateImage( cvGetSize(src), 8, 1 );
13 IplImage* color_dst = cvCreateImage( cvGetSize(src), 8, 3 );
14 CvMemStorage* storage = cvCreateMemStorage(0);
15 CvSeq* lines = 0;
16 int i;
17 IplImage* src1=cvCreateImage(cvSize(src->width,src->height),IPL_DEPTH_8U,1);
18 cvCvtColor(src, src1, CV_BGR2GRAY);
19 cvCanny( src1, dst, 50, 200, 3 );
20 cvCvtColor( dst, color_dst, CV_GRAY2BGR );
21 #if 1
22 lines = cvHoughLines2( dst, storage, CV_HOUGH_STANDARD, 1, CV_PI/180, 150, 0, 0 );
23 for( i = 0; i < lines->total; i++ )
24 {
25 float* line = (float*)cvGetSeqElem(lines,i);
26 float rho = line[0];
27 float theta = line[1];
28 CvPoint pt1, pt2;
29 double a = cos(theta), b = sin(theta);
30 if( fabs(a) < 0.001 )
31 {
32 pt1.x = pt2.x = cvRound(rho);
33 pt1.y = 0;
34 pt2.y = color_dst->height;
35 }
36 else if( fabs(b) < 0.001 )
37 {
38 pt1.y = pt2.y = cvRound(rho);
39 pt1.x = 0;
40 pt2.x = color_dst->width;
41 }
42 else
43 {
44 pt1.x = 0;
45 pt1.y = cvRound(rho/b);
46 pt2.x = cvRound(rho/a);
47 pt2.y = 0;
48 }
49 cvLine( color_dst, pt1, pt2, CV_RGB(255,0,0), 3, 8 );
50 }
51 #else
52 lines = cvHoughLines2( dst, storage, CV_HOUGH_PROBABILISTIC, 1, CV_PI/180, 80, 30, 10 );
53 for( i = 0; i < lines->total; i++ )
54 {
55 CvPoint* line = (CvPoint*)cvGetSeqElem(lines,i);
56 cvLine( color_dst, line[0], line[1], CV_RGB(255,0,0), 3, 8 );
57 }
58 #endif
59 cvNamedWindow( "Source", 1 );
60 cvShowImage( "Source", src );
61 cvNamedWindow( "Hough", 1 );
62 cvShowImage( "Hough", color_dst );
63 cvWaitKey(0);
64 }

霍夫直线变换Example

 

  

结果图片：

 

  

要言妙道：

 ①使用cvHoughCircles前注意对图像适当的处理，例如：cvSmooth

②使用cvHoughLines2前注意使用cvCanny

③注意cvHoughLines2的另两种method，CV_HOUGH_STANDARD,CV_HOUTH_MULTI_SCALE及各自的用法及参数意义