在OpenCV中利用鼠標繪制直線

在這裡不多說了，直接貼代碼。希望對大家學習OpenCV有用，歡迎大家的建議！

1. #include <cv.h>
2. #include <highgui.h>
3. #include <stdio.h>
4. #pragma comment( lib, "cv.lib" )
5. #pragma comment( lib, "cxcore.lib" )
6. #pragma comment( lib, "highgui.lib" )
7. IplImage* src = 0;
8. IplImage* dst = 0;
9. void on_mouse( int event, int x, int y, int flags, void* ustc)
10. {
11. static CvPoint pre_pt = {-1,-1};
12. static CvPoint cur_pt = {-1,-1};
13. CvFont font;
14. cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);
15. char temp[16];
17. if( event == CV_EVENT_LBUTTONDOWN )
18. {
19. cvCopy(dst,src);
20. sprintf(temp,"(%d,%d)",x,y);
21. pre_pt = cvPoint(x,y);
22. cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255));
23. cvCircle( src, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
24. cvShowImage( "src", src );
25. cvCopy(src,dst);
26. }
27. else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
28. {
29. cvCopy(dst,src);
30. sprintf(temp,"(%d,%d)",x,y);
31. cur_pt = cvPoint(x,y);
32. cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
33. cvLine(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, CV_AA, 0 );
34. cvShowImage( "src", src );
35. }
36. else if( event == CV_EVENT_LBUTTONUP )
37. {
38. sprintf(temp,"(%d,%d)",x,y);
39. cur_pt = cvPoint(x,y);
40. cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
41. cvCircle( src, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
42. cvLine( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, CV_AA, 0 );
43. cvShowImage( "src", src );
44. cvCopy(src,dst);
45. }
46. }
47. int main()
48. {
49. src=cvLoadImage("lena.jpg",1);
50. dst=cvCloneImage(src);
51. cvNamedWindow("src",1);
52. cvSetMouseCallback( "src", on_mouse, 0 );
54. cvShowImage("src",src);
55. cvWaitKey(0);
56. cvDestroyAllWindows();
57. cvReleaseImage(&src);
58. cvReleaseImage(&dst);
59. return 0;
60. }

效果圖如下，說明一下這裡的坐標原點是圖像的左上角。