Learning opencv--mouse events (picture frames)

[CPP]View PlainCopyprint?

2. #include "Cv.h"
4. #include "highgui.h"
8. BOOL check_line_state=false;
10. Iplimage* workimg;
12. Iplimage* imgshow;
14. Cvrect Roi_rect;
18. void On_mouse4 (int event, int x,int y,int flags,void* param)
20. {
22. int thickness=2;
24. Cvpoint P1,P2;
26. if (event==cv_event_lbuttondown)
28. {
30. //Current mouse position (x, y)
32. Roi_rect.x=x;
34. Roi_rect.y=y;
36. Check_line_state=true;
38. }
40. Else if (check_line_state&&event==cv_event_mousemove)//mouse state
42. {
44. Cvcopy (workimg,imgshow); //This step is important to constantly update the display image, otherwise the picture shown in Figure 2
46. P1=cvpoint (ROI_RECT.X,ROI_RECT.Y);
48. P2=cvpoint (x, y);
50. Cvrectangle (Imgshow,p1,p2,cv_rgb (0,255,150), thickness,cv_aa,0);
52. Cvshowimage ("image", imgshow);
56. }
58. Else if (check_line_state&&event==cv_event_lbuttonup)
60. {
62. Check_line_state=false;
64. Cvwaitkey (20);
66. }
68. }
72. int main ()
74. {
76. Workimg=cvloadimage ("d:/demo.jpg", 1);
78. Imgshow=cvcreateimage (Cvsize (workimg->width,workimg->height), workimg->depth,workimg->nchannels);
80. Cvcopy (workimg,imgshow);
82. //cvflip (imgshow);
86. roi_rect.x=roi_rect.y=0;
88. Cvnamedwindow ("image", cv_window_autosize);
90. Cvshowimage ("image", imgshow);
94. Cvsetmousecallback ("image", on_mouse4);
98. Cvwaitkey ();
100. Cvdestroywindow ("image");
102. }

Figure 1: Figure 2:

from:http://blog.csdn.net/yangtrees/article/details/7573919

Learning opencv--mouse events (picture frames)