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Using BackgroundSubtractorMOG2 for images


I am pretty new to OpenCV and I am stuck at the moment. Since I will have same background in my project, I thought it would be easier to work, if I could remove my background. But first, I have to ask one thing. Can I use BackgroundSubtractorMOG2 for images? Because it is under video analysis/motion analysis title.

I read the documentation on and looked through countless examples/tutorials but I am still having difficulty understanding how MOG2 works.

Quick question: What is history that in parameters?

So, I have written a simple code. I get a foreground mask. So, what is next step? How can I remove the background and left with my object only? Shouldn't I load my background first, then the actual image, so that MOG2 could do the background subtraction?

I am using OpenCV 2.4.11.

Thanks in advance.


#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/video/background_segm.hpp>

using namespace cv;
using namespace std;

//global variables
int history = 1;
float varThreshold = 16;
bool bShadowDetection = true;

Mat src; //source image
Mat fgMaskMOG2; //fg mask generated by MOG2 method
Ptr<BackgroundSubtractor> pMOG2; //MOG2 Background subtractor

int main(int argc, char* argv[])
    //create GUI windows
    namedWindow("FG Mask MOG 2");

    src = imread("bluePaper1.png", 1);

    //create Background Subtractor objects
    pMOG2 = new BackgroundSubtractorMOG2(history, varThreshold, bShadowDetection); //MOG2 approach
    pMOG2->setInt("nmixtures", 3);
    pMOG2->setDouble("fTau", 0.5);

    pMOG2->operator()(src, fgMaskMOG2);

    imshow("Source", src);
    imshow("FG Mask MOG 2", fgMaskMOG2);


    return 0;

Source image:


fgMask that I get from MOG2: fgMask.png