Questions tagged [sift]

59 questions
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What is the story behind the story about SIFT descriptor?

The following is from Lowe 2004 paper ( http://www.cs.ubc.ca/~lowe/papers/ijcv04.pdf ). One obvious approach would be to sample the local image intensities around the keypoint at the appropriate scale, and to match these using a normalized…
jakeoung
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I have a question on SIFT

I am reading a paper on SIFT by Lowe. In it, gradient magnitudes and orientations are calculated using these formulae: $$$$ I don't know why m(x,y) is calculated above. I heard that gradient magnitude is usually calculated like the…
jakeoung
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Are there algorithms that can match SIFT's key points of 2 images using their mutual arrangement?

I'm solving image matching task using SIFT as a feature extractor To match obtained descriptors I used FLANN based Matcher (provided by OpenCV) and result looks good: But applying same algorithm to different images I still have some "False…