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c++opencvcomputer-sciencesift

Compute Dense SIFT features in OpenCV 3.0

Since version 3.0, DenseFeatureDetector is no longer available. Could anybody please show me how to compute Dense SIFT features in OpenCV 3.0? I couldn't find it in the documentation.

Thank you very much in advance!

Solution

  • Here's how I used dense SIFT in OpenCV 3 C++:

    SiftDescriptorExtractor sift;

vector<KeyPoint> keypoints; // keypoint storage
Mat descriptors; // descriptor storage

// manual keypoint grid

int step = 10; // 10 pixels spacing between kp's

for (int y=step; y<img.rows-step; y+=step){
    for (int x=step; x<img.cols-step; x+=step){

        // x,y,radius
        keypoints.push_back(KeyPoint(float(x), float(y), float(step)));
    }
}

// compute descriptors

sift.compute(img, keypoints, descriptors);

    copied from: http://answers.opencv.org/question/73165/compute-dense-sift-features-in-opencv-30/?answer=73178#post-id-73178

    seems to work well