void Features::extract(const cv::DescriptorExtractor& extract, const cv::Mat& img)
{
extract.compute(img, kpts_, descriptors_);
KeyPointsToPoints(kpts_, pts_);
// matcher_->add(vector<Mat>(1,descriptors_));
// matcher_->train();
}
void compute_descriptors(cv::Mat &image, vector<ImageFeature> & features, std::string & name, cv::DescriptorExtractor & extractor,
cv::Mat &descriptors, std::vector<cv::KeyPoint>& keypoints) {
features_to_keypoints(features, keypoints);
extractor.compute(image, keypoints, descriptors);
}