KalmanFilterExampleSimple

#include "stdafx.h"
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/video/tracking.hpp>

using namespace cv;
using namespace std;

// plot points
#define drawCross( center, color, d )                                 \
line( img, Point( center.x - d, center.y - d ),                \
Point( center.x + d, center.y + d ), color, 2, CV_AA, 0); \
line( img, Point( center.x + d, center.y - d ),                \
Point( center.x - d, center.y + d ), color, 2, CV_AA, 0 )

struct mouse_info_struct { int x,y; };
struct mouse_info_struct mouse_info = {-1,-1};

vector<Point> mousev,kalmanv;

KalmanFilter KF;

void on_mouse(int event, int x, int y, int flags, void* param) {
    {
        mouse_info.x = x;
        mouse_info.y = y;
    }
}

void reset(){

    /*
    KF.statePre.at<float>(0) = mouse_info.x;
    KF.statePre.at<float>(1) = mouse_info.y;
    KF.statePre.at<float>(2) = 0;
    KF.statePre.at<float>(3) = 0;
    KF.transitionMatrix = *(Mat_<float>(4, 4) << 1,0,0,0,   0,1,0,0,  0,0,1,0,  0,0,0,1);
    //*/
    setIdentity(KF.measurementMatrix);
    setIdentity(KF.processNoiseCov, Scalar::all(1e-4));
    setIdentity(KF.measurementNoiseCov, Scalar::all(1e-1));
    setIdentity(KF.errorCovPost, Scalar::all(.1));

    mousev.clear();
    kalmanv.clear();
}

int _tmain(int argc, _TCHAR* argv[])
{
    Mat img(500, 500, CV_8UC3);
    KF = *(new KalmanFilter(4, 2, 0));
    //Mat_<float> state(4, 1); //(x, y, Vx, Vy)
    //Mat processNoise(4, 1, CV_32F);
    Mat_<float> measurement(2,1); measurement.setTo(Scalar(0));
    char code = (char)-1;

    namedWindow("mk");
    setMouseCallback("mk", on_mouse, 0);
    reset();
    for(;;)
    {
        KF.predict();

        measurement(0) = mouse_info.x;
        measurement(1) = mouse_info.y;

        Point measPt(measurement(0),measurement(1));
        mousev.push_back(measPt);

        Mat estimated = KF.correct(measurement);
        Point statePt(estimated.at<float>(0),estimated.at<float>(1));
        kalmanv.push_back(statePt);

        img = Scalar::all(0);
        drawCross( statePt, Scalar(255,255,255), 5 );
        drawCross( measPt, Scalar(0,0,255), 5 );

        for (int i = 0; i < mousev.size()-1; i++) {
            line(img, mousev[i], mousev[i+1], Scalar(255,255,0), 1);
        }
        for (int i = 0; i < kalmanv.size()-1; i++) {
            line(img, kalmanv[i], kalmanv[i+1], Scalar(0,255,0), 1);
        }

        imshow( "mk", img );
        code = (char)waitKey(100);

        if( code > 0) reset();
        if( code == 27) break;
    }
    return 0;
}