OpenCV descriptor removes keypoint

4
votes

OpenCV 2.4 has detector and descriptor. I am creating keypoints for a lot of images and the problem is that the detector gets the keypoints but the descriptor sometimes removes them all.

  • How do I disable the descriptor from removing the points?
  • Is there a way to enhance the key points so that they are not removed?

Knowing that i tried a lot of descriptors (SIFT, SURF, BRIEF, etc ...)

1
pythonopencvcomputer-visionfeature-detectionkeypoint

1 Answers

0
votes

Can you post some code? A CPU implementation can be found in the samples/cpp folder called matcher_simple.cpp. Are you able to run that? I also have run the GPU version of SURF on OpenCV with no problem using:

SURF_GPU surf(1000, 4, 2, false, 0.5);

// detecting keypoints & computing descriptors
GpuMat keypoints1GPU, keypoints2GPU;
GpuMat descriptors1GPU, descriptors2GPU;
surf(img1, GpuMat(), keypoints1GPU, descriptors1GPU);
surf(img2, GpuMat(), keypoints2GPU, descriptors2GPU);

cout << "FOUND " << keypoints1GPU.cols << " keypoints on first image" << endl;
cout << "FOUND " << keypoints2GPU.cols << " keypoints on second image" << endl;

// matching descriptors
BruteForceMatcher_GPU< L2<float> > matcher;
GpuMat trainIdx, distance;
matcher.matchSingle(descriptors1GPU, descriptors2GPU, trainIdx, distance);

// downloading results
vector<KeyPoint> keypoints1, keypoints2;
vector<float> descriptors1, descriptors2;
vector<DMatch> matches;
surf.downloadKeypoints(keypoints1GPU, keypoints1);
surf.downloadKeypoints(keypoints2GPU, keypoints2);
surf.downloadDescriptors(descriptors1GPU, descriptors1);
surf.downloadDescriptors(descriptors2GPU, descriptors2);
BruteForceMatcher_GPU< L2<float> >::matchDownload(trainIdx, distance, matches);

// drawing the results
Mat img_matches, image1, image2;
img1.download(image1);
img2.download(image2);
drawMatches(image1, keypoints1, image2, keypoints2, matches, img_matches);