6wV8mytW

1#include <opencv2/core.hpp>
2#include <opencv2/videoio.hpp>
3#include <opencv2/highgui.hpp>
4#include <iostream>
5
6using namespace cv;
7using namespace std;
8
9void merge_images(cv::Mat* background, cv::Mat* upcoming, int x, int y)
10{
11  auto handle_cv_8uc4 = [=](int i, int j)
12  {
13
14    if(upcoming->at<cv::Vec4b>(j, i)[3] > 10)//10 is only epsilon for trash hold, you can put also 0 or anything else.
15    {
16      background->at<cv::Vec4b>(y+j, x+i) = upcoming->at<cv::Vec4b>(j, i);
17    }
18  };
19
20  auto handle_cv_8uc3 = [=](int i, int j)
21  {
22    background->at<cv::Vec4b>(y+j, x+i)[0] = upcoming->at<cv::Vec3b>(j, i)[0];
23    background->at<cv::Vec4b>(y+j, x+i)[1] = upcoming->at<cv::Vec3b>(j, i)[1];
24    background->at<cv::Vec4b>(y+j, x+i)[2] = upcoming->at<cv::Vec3b>(j, i)[2];
25    background->at<cv::Vec4b>(y+j, x+i)[3] = 255;
26  };
27
28  for(int i = 0; i < upcoming->cols; i++)
29  {
30    for(int j = 0; j < upcoming->rows; j++)
31    {
32      if(j + y >= background->rows)
33      {
34        break;
35      }
36
37      if(x + i >= background->cols)
38      {
39        return;
40      }
41
42      switch(upcoming->channels())
43      {
44        case 3:
45        {
46          handle_cv_8uc3(i, j);
47          break;
48        }
49
50        case 4:
51        {
52          handle_cv_8uc4(i, j);
53          break;
54        }
55
56        default:
57        {
58          //maybe error?
59        }
60      }
61
62    }
63  }
64}
65
66int main(int, char**)
67{
68  Mat frame;
69  //--- INITIALIZE VIDEOCAPTURE
70  VideoCapture cap;
71  // open the default camera using default API
72  // cap.open(0);
73  // OR advance usage: select any API backend
74  int deviceID = 0;             // 0 = open default camera
75  int apiID = cv::CAP_ANY;      // 0 = autodetect default API
76  // open selected camera using selected API
77  cap.open(deviceID, apiID);
78  // check if we succeeded
79  if (!cap.isOpened()) {
80    cerr << "ERROR! Unable to open camera\n";
81    return -1;
82  }
83  //--- GRAB AND WRITE LOOP
84  cout << "Start grabbing" << endl
85       << "Press any key to terminate" << endl;
86
87  auto background = imread("index.png");
88  for (;;)
89  {
90    // wait for a new frame from camera and store it into 'frame'
91    cap.read(frame);
92    cv::Mat dst(background.rows, background.cols, CV_8UC4);
93    merge_images(&dst, &background, 0, 0);
94    merge_images(&frame, &dst, 50, 50);
95    // check if we succeeded
96    if (frame.empty()) {
97      cerr << "ERROR! blank frame grabbed\n";
98      break;
99    }
100    // show live and wait for a key with timeout long enough to show images
101
102    imshow("underlay result", frame);
103    if (waitKey(5) >= 0)
104      break;
105  }
106  // the camera will be deinitialized automatically in VideoCapture destructor
107  return 0;
108}