This file uses a test solution of the question mentioned at: http://answers.opencv.org/question/139888/removing-noise-from-contour-features-in-real-time/

check_interpolation.cpp

#include <iostream>
#include <opencv2/highgui.hpp>
#include <deque>

using namespace cv;
using namespace std; 

//
// e.g. to smooth noisy landmarks ;)
//
template<class T>
struct Ipol
{
    size_t N;
    std::deque<T> q;

    Ipol(size_t n=10) : N(n) {}

    T operator ()(T t)
    {
        q.push_back(t);
        if (q.size() > N)
            q.pop_front();

        T acc(0,0);
        for (size_t i=0; i<q.size(); ++i)
            acc += q[i];
        return acc / double(q.size());
    }
};

int nInterpolations = 5;
vector<Ipol<Point>> ipo(4, nInterpolations); // one for each box corner

/*while(true) {
    ... process image, find contours, retrieve box points
    for each box point:
         Point newVertex = ipo[i](oldVertex);
 }*/

int main ()
{
    Point x[4];
    for (int i = 0; i < 4; i++)
    {
        int rand1 = rand();
        int rand2 = rand();
        x[i] = Point (rand1, rand2);
        cout << "Before" << x[i] << endl;
        Point mod_x = ipo[i](x[i]);
        x[i] = mod_x;
        cout << "After" << x[i] << endl;
    }

    return 0;
}