OpenCV saving image, keypoints and descriptors to file
c++, flann, image-processing, opencv, surf
Solution
you have to write them one at a time:
FileStorage fs("Keypoints.yml", FileStorage::WRITE);
write(fs, "keypoints_1", keypoints_1);
write(fs, "descriptors_1", tempDescriptors_1);
...
fs.release();
Problem
I'm using SURF/FLANN detector and I'm looking to save the image, points, descriptors to a file so I can then compare this image and it's points to a second image and points however I'm getting the following error when I try to write: ``` In file included from detectFlannPoints.cpp:4:0: /usr/local/include/opencv2/features2d/features2d.hpp:112:17: note: void cv::write(cv::FileStorage&, const string&, const std::vector<cv::KeyPoint>&) /usr/local/include/opencv2/features2d/features2d.hpp:112:17: note: candidate expects 3 arguments, 4 provided ``` This is the code I'm using to write: ``` FileStorage fs("Keypoints.yml", FileStorage::WRITE); write(fs, "templateImageOne", keypoints_1, tempDescriptors_1); fs.release(); ``` I'm not sure where I can specify the extra argument (`tempDescriptors_1`) as it works fine with this arg removed. Code immediatly above the write code: ``` //Detect the keypoints using SURF Detector int minHessian = 400; SurfFeatureDetector detector( minHessian ); std::vector<KeyPoint> keypoints_1; detector.detect( img_1, keypoints_1 ); //-- Step 2: Calculate descriptors (feature vectors) SurfDescriptorExtractor extractor; Mat tempDescriptors_1; extractor.compute( img_1, keypoints_1, tempDescriptors_1 ); //-- Draw keypoints Mat img_keypoints_1; drawKeypoints( img_1, keypoints_1, img_keypoints_1, Scalar::all(-1), DrawMatchesFlags::DEFAULT ); ```