OpenCV 圖像陰影檢測

參數說明：

IplImage *workImg-當前全局變量,表示正在顯示的圖片。

downleft, upright- 檢測出的陰影部分矩形框的兩個對角頂點。

1. /*********************************************/
2. //陰影檢測
3. /*********************************************/
5. CvPoint downleft,upright;
6. int cnt;
7. int dir[8][2]={-1,-1,-1,0,-1,1,0,1,0,-1,1,1,1,0,1,-1};
8. #define SHADOW 170
9. #define Thres_KindNumber 20
11. bool InRange(CvPoint point,IplImage* pi)
12. {
13. int w=pi->width;
14. int h=pi->height;
15. if(point.x>=0&&point.x<w&&point.y>=0&&point.y<h)
16. {
17. float v[3];
18. for(i=0;i<3;i++)
19. {
20. v[i]=((uchar*)(pi->imageData + pi->widthStep*point.y))[point.x*3+i];
21. if(v[i]<=SHADOW)
22. return true;
23. }
24. }
25. return false;
26. }
28. void Dye(IplImage** curimg,CvPoint s)
29. {
30. int i;
31. queue<CvPoint>Q;
32. Q.push(s);
34. for(i=0;i<3;i++)
35. ((uchar*)((*curimg)->imageData + (*curimg)->widthStep*s.y))[s.x*3+i]=SHADOW+10;
37. while(!Q.empty())
38. {
39. s=Q.front();
40. Q.pop();
42. if(s.x<downleft.x) downleft.x=s.x;
43. if(s.y<downleft.y) downleft.y=s.y;
44. if(s.x>upright.x) upright.x=s.x;
45. if(s.y>upright.y) upright.y=s.y;
47. //dye around
48. for(i=0;i<8;i++)
49. {
50. CvPoint now=cvPoint(s.x+dir[i][0],s.y+dir[i][1]);
51. if(InRange(now,*curimg))
52. {
53. Q.push(now);
54. cnt++;
55. for(i=0;i<3;i++)
56. ((uchar*)((*curimg)->imageData + (*curimg)->widthStep*now.y))[now.x*3+i]=SHADOW+10;
57. }
58. }
59. }
60. }
62. void CCVMFCView::OnShadowDetect()
63. {
64. //detect shadows,find the region with highest pixel value
65. int x,y;
66. srcimg=workImg;
67. for(y=0;y<srcimg->height;y++)
68. for(x=0;x<srcimg->width;x++)
69. {
70. CvPoint curp=cvPoint(x,y);
71. downleft.x=srcimg->width;downleft.y=srcimg->height;
72. upright.x=upright.y=0;
73. cnt=0;
75. if(InRange(curp,srcimg))
76. Dye(&srcimg,curp);
77. if(cnt>Thres_KindNumber)
78. cvRectangle(workImg , downleft,upright,CV_RGB(0,255,0),1,CV_AA,0);
79. }
80. Invalidate();
81. }