opencv - how to save Mat image in filestorage

Question

I want to save a floating point one-channel image and I don't want to convert it. So I decided to use filestorage class to save it but I couldn't quite get how to do it from the documentation. And what I tried didn't work. Can anybody help me with this?

// Write:
FileStorage fs("img.xml", FileStorage::WRITE);
Mat img;
fs << img;

// Read:
FileStorage fs("img.xml", FileStorage::READ);
Mat img;
fs >> img;

Answer 1

Writing to file

cv::FileStorage storage("test.yml", cv::FileStorage::WRITE);
storage << "img" << img;
storage.release();  

Reading from file

cv::FileStorage storage("test.yml", cv::FileStorage::READ);
storage["img"] >> img;
storage.release();