asked 2014-05-23 07:30:15 -0500

Junglee gravatar image

updated 2014-05-23 07:36:34 -0500

Hi All,

i have tried below example to subtract Image's background, its working well and updates position of the object but for the first time i mean when camera starts if i move an object from its initial position to some other position, its initial position Blob is not getting erased. i have attached image for your reference, what am i missing to clear that Initial Position of Original object. Here's my code:

#include <opencv2/highgui/highgui.hpp>
#include <opencv2/video/background_segm.hpp>
#include <opencv2/video/video.hpp>
#include <iostream>
#include <sstream>
using namespace cv;
using namespace std;

//global variables
Mat frame; //current frame
Mat fgMaskMOG; //fg mask generated by MOG method
Mat fgMaskMOG2; //fg mask fg mask generated by MOG2 method
Ptr<BackgroundSubtractor> pMOG; //MOG Background subtractor
Ptr<BackgroundSubtractor> pMOG2; //MOG2 Background subtractor
int keyboard;

//function declarations
void processVideo();

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

//create Background Subtractor objects
pMOG = new BackgroundSubtractorMOG(); //MOG approach
pMOG2 = new BackgroundSubtractorMOG2(); //MOG2 approach

//input data coming from a video

//destroy GUI windows

void processVideo() 
//create the capture object
VideoCapture capture;;
    //error in opening the video input
    cerr << "Unable to open video Camera " << endl;
//read input data. ESC or 'q' for quitting
while( (char)keyboard != 'q' && (char)keyboard != 27 ){
    //read the current frame
    if(! {
        cerr << "Unable to read next frame." << endl;
        cerr << "Exiting..." << endl;
    //update the background model
    pMOG->operator()(frame, fgMaskMOG);
    pMOG2->operator()(frame, fgMaskMOG2);
    //get the frame number and write it on the current frame
    stringstream ss;
    rectangle(frame, cv::Point(10, 2), cv::Point(100,20),cv::Scalar(255,255,255), -1);
    ss << capture.get(CV_CAP_PROP_POS_FRAMES);
    string frameNumberString = ss.str();
    putText(frame, frameNumberString.c_str(), cv::Point(15, 15),
                    FONT_HERSHEY_SIMPLEX, 0.5 , cv::Scalar(0,0,0));
    //show the current frame and the fg masks
    imshow("Frame", frame);
    imshow("FG Mask MOG", fgMaskMOG);
    imshow("FG Mask MOG 2", fgMaskMOG2);
    //get the input from the keyboard
    keyboard = waitKey( 30 );
//delete capture object

Here's my Image:

image description

edit retag flag offensive close merge delete


You probably need to wait until the background model adapts to the new appearance there. Or you may want to use a different background modeling approach. Perhaps a simple thresholded absolute difference with an empty scene is enough.

isarandi gravatar imageisarandi ( 2014-05-23 12:09:43 -0500 )edit

@isarandi, I didn't get you can you please elaborate.

Junglee gravatar imageJunglee ( 2014-05-25 23:46:31 -0500 )edit

@Junglee What is your application about, what is your goal? How long did you wait for it to disappear?

isarandi gravatar imageisarandi ( 2014-05-26 06:17:04 -0500 )edit