// Find best matches for each query descriptor which have distance less than maxDistance (in increasing order of distances).
void radiusMatch( InputArray queryImage, std::vector<KeyPoint>& queryKeypoints,
InputArray trainImage, std::vector<KeyPoint>& trainKeypoints,
std::vector<std::vector<DMatch> >& matches, float maxDistance,
// Find best matches for each query descriptor which have distance less than maxDistance (in increasing order of distances).
void radiusMatch( InputArray queryImage, std::vector<KeyPoint>& queryKeypoints,
InputArray trainImage, std::vector<KeyPoint>& trainKeypoints,
std::vector<std::vector<DMatch> >& matches, float maxDistance,