MovingAverage_BackgroundSubtraction.cpp

#include <vector>
#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;


void draw_rect(Mat& img, vector< Rect >& v_rect) {

	for (auto it : v_rect) {
		rectangle(img, it, CV_RGB(255, 0, 0), 2);
	}
}




int main(int, char)
{


	//Mat absdiff_frame;
	VideoCapture stream1(1);

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

	Mat frame;
	Mat PR_img_gray;
	Mat sub_frame;
	Mat BG_img_gray;
	int frame_flow = 50;
	int count_frame = 0;
	float min_area_percent = 0.1;
	float min_window_area;
	float alpha = 0.1;
	float beta = (1.0 - alpha);

	namedWindow("frame", 0);
	namedWindow("sub_frame", 0);
	namedWindow("BG_frame", 0);

	while (1)
	{

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

		//frame flow
		if (BG_img_gray.empty()) {
			cvtColor(frame.clone(), BG_img_gray, COLOR_BGR2GRAY);
			min_window_area = BG_img_gray.size().area() * min_area_percent / 100.0;
		}

		
		cvtColor(frame.clone(), PR_img_gray, COLOR_BGR2GRAY);	
		addWeighted(PR_img_gray, alpha, BG_img_gray, beta, 0.0, BG_img_gray);

		if (count_frame < frame_flow)
		{
			count_frame++;
			printf("calibration %d\n", count_frame);
			continue;
		}


		//subtract(old_frame, frame, sub_frame);
		absdiff(BG_img_gray, PR_img_gray, sub_frame);
		threshold(sub_frame, sub_frame, 70, 255, THRESH_BINARY);

		//find contour
		vector< vector< Point> > contours;
		vector< Vec4i> hierarchy;
		findContours(sub_frame.clone(), contours, hierarchy, RETR_CCOMP, CHAIN_APPROX_SIMPLE);
		//drawContours(frame, contours, -1, CV_RGB(255, 0, 0), 5, 8, hierarchy);

		//Blob labeling
		vector< Rect > v_rect;
		for (auto it : contours) {

			double area = contourArea(it, false);
			if (area > min_window_area)
			{
				Rect mr = boundingRect(Mat(it));
				v_rect.push_back(mr);
				//printf("%lf\n", area);
			}
		}
		draw_rect(frame, v_rect);

		//
		imshow("frame", frame);
		imshow("sub_frame", sub_frame);
		imshow("BG_frame", BG_img_gray);


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

	return 0;
}