OpneCV_simple_background_subtraction.cpp

//http://study.marearts.com/2019/04/opencv-simple-background-subtraction.html
//https://youtu.be/s32FB0OxnuI

#include <opencv2/opencv.hpp>

#ifdef _DEBUG  
#pragma comment(lib, "opencv_world401d.lib")
#else
#pragma comment(lib, "opencv_world401.lib")
#endif 
 

using namespace cv;
using namespace std;


using namespace std;
using namespace cv;

int main(int, char)
{
	Mat frame;
	Mat old_frame;
	
	//Mat absdiff_frame;
	VideoCapture stream1(0);

	if (!stream1.isOpened()) { //check if video device has been initialised
		cout << "cannot open camera 1";
	}

	Mat PR_img;
	Mat sub_frame;
	Mat BG_img;
	int frame_flow = 50;
	int count_frame = 0;

	

	while (1)
	{

		if (!(stream1.read(frame))) //get one frame form video   
			break;

		//frame flow
		if (BG_img.empty()) {
			if (count_frame < frame_flow)
			{
				count_frame++;
				printf("calibration %d\n", count_frame);
				continue;
			}
			else {
				BG_img = frame.clone();
				cvtColor(BG_img, BG_img, COLOR_BGR2GRAY);
			}
		}

		PR_img = frame.clone();
		cvtColor(PR_img, PR_img, COLOR_BGR2GRAY);
		

		//subtract(old_frame, frame, sub_frame);
		absdiff(BG_img, PR_img, sub_frame);

		imshow("frame", frame);
		imshow("sub_frame", sub_frame);
		imshow("BG_frame", BG_img);


		if (waitKey(5) >= 0)
			break;
	}

	return 0;
}

http://study.marearts.com/2019/04/opencv-simple-background-subtraction.html
https://youtu.be/s32FB0OxnuI