opencv 绿幕视频背景替换

基于hsv颜色空间的实时背景替换： 

1. #include

2. using namespace cv;

3. Mat replace_and_blend(Mat &frame, Mat&mask);

4. Mat background,frame, hsv, mask,result;

5. int main(int arc, char** argv) {

6. background = imread("2.jpg");

7. namedWindow("input", CV_WINDOW_AUTOSIZE);

8. imshow("src", background);

9.  

10. VideoCapture capture;

11. capture.open("1.mp4");

12. while (capture.read(frame)) {

13. imshow("input", frame);

14. cvtColor(frame, hsv, CV_BGR2HSV);

15. inRange(hsv, Scalar(35, 43, 46), Scalar(77, 255, 255), mask);//颜色过滤，得到mask绿色部分为1，其它部分都为0

16. imshow("mask", mask);

17. Mat kernel = getStructuringElement(MORPH_RECT,Size(3,3));

18. morphologyEx(mask, mask, MORPH_DILATE, kernel);

19. GaussianBlur(mask, mask, Size(3, 3), 0, 0);//0,0会根据Size自动算的

20.  

21. result = replace_and_blend(frame, mask);

22.  

23. char c = waitKey(1);

24. if (c == 27) {

25. break;

26. }

27. imshow("input", frame);

28. imshow("result", result);

29. }

30. waitKey(0);

31. return 0;

32. }

33.  

34. Mat replace_and_blend(Mat &frame, Mat&mask) {

35. result = Mat::zeros(frame.size(), frame.type());

36. int h = frame.rows;

37. int w = frame.cols;

38. int dims = frame.channels();

39.  

40. int m ;

41. double wt ;

42. int b , g, r;

43. int b1, g1, r1;

44. int b2 , g2, r2 ;

45. //指针操作速度最快，直接访问地址

46. for (int row = 0; row < h; row++) {

47. uchar* current = frame.ptr(row);

48. uchar* bgrow = background.ptr(row);

49. uchar* maskrow = mask.ptr(row);

50. uchar* targetrow = result.ptr(row);

51. for (int col = 0; col < w; col++) {

52. m = *maskrow++;

53. if (m == 255) {//背景

54. *targetrow++ = *bgrow++;

55. *targetrow++ = *bgrow++;

56. *targetrow++ = *bgrow++;

57. current += 3;

58. }

59. else if (m == 0) {//前景

60. *targetrow++ = *current++;

61. *targetrow++ = *current++;

62. *targetrow++ = *current++;

63. bgrow += 3;

64. }

65. else {

66. b1 = *bgrow++;

67. g1 = *bgrow++;

68. r1 = *bgrow++;

69.  

70. b2 = *current++;

71. g2 = *current++;

72. r2 = *current++;

73.  

74. wt = m/ 255.0;

75. b = wt*b1 + (1 - wt)*b2;

76. g = wt*g1 + (1 - wt)*g2;

77. r = wt*r1 + (1 - wt)*r2;

78.  

79. *targetrow++ = b;

80. *targetrow++ = g;

81. *targetrow++ = r;

82. }

83. }

84. }

85. return result;

86. }

 

参考文献：https://blog.csdn.net/huanghuangjin/article/details/81461040