to remove outliers from the matching algorithms

good_matches.h

    void filterMatches(const std::vector<cv::DMatch> matches,const std::vector<cv::KeyPoint>&keypoints1,const std::vector<cv::KeyPoint>& keypoints2,std::vector<cv::DMatch>& goodMatches,double dist,double confidence_interval)
    {
        goodMatches.clear();
        // converting keypoints to just 2D points
        std::vector<cv::Point2f> points1, points2;
        for (std::vector<cv::DMatch>::const_iterator it= matches.begin();it!= matches.end(); ++it)
        {
            // from de matches, extract just the keypoints of the left frame
            float x= keypoints1[it->queryIdx].pt.x;
            float y= keypoints1[it->queryIdx].pt.y;
            points1.push_back(cv::Point2f(x,y));

            // from de matches, extract just the keypoints of the left frame
            x= keypoints2[it->trainIdx].pt.x;
            y= keypoints2[it->trainIdx].pt.y;
            points2.push_back(cv::Point2f(x,y));
        }
        // calculating the Fundamental mat with the ransac algorithm
        std::vector<uchar> inliers(points1.size(),0);

        cv::Mat fundamental= cv::findFundamentalMat(cv::Mat(points1),cv::Mat(points2),inliers,CV_FM_RANSAC,dist,confidence_interval); // intervalo de confianca

        // with the inliers, choose from the matches only the "good" ones
        std::vector<uchar>::const_iterator
        itIn= inliers.begin();
        std::vector<cv::DMatch>::const_iterator
        itM= matches.begin();
        // for all matches
        for ( ;itIn!= inliers.end(); ++itIn, ++itM)
        {
            if (*itIn)
            { // it is a valid match
                goodMatches.push_back(*itM);
            }
        }
    }
    
    void keypoints2points(std::vector<cv::Point2f> &points1,std::vector<cv::Point2f> &points2,const std::vector<cv::KeyPoint>&keypoints1,const std::vector<cv::KeyPoint>&keypoints2,const std::vector<cv::DMatch> matches)
{
        for (std::vector<cv::DMatch>::const_iterator it= matches.begin();it!= matches.end(); ++it)
        {
            float x,y;

            // from the matches, extract just the keypoints of the left frame
            x= keypoints1[it->queryIdx].pt.x;
            y= keypoints1[it->queryIdx].pt.y;
            points1.push_back(cv::Point2f(x,y));

            // from the matches, extract just the keypoints of the right frame
            x= keypoints2[it->trainIdx].pt.x;
            y= keypoints2[it->trainIdx].pt.y;
            points2.push_back(cv::Point2f(x,y));
        }
}