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isift

SIFT feature extractor

sf = isift(im, options) is a vector of SiftPointFeature objects representing scale and rotationally invariant interest points in the image im.

Options

'nfeat', N set the number of features to return (default Inf)
'suppress', R set the suppression radius (default 0)
'id', V set the image_id of all features

Properties and methods

The SiftPointFeature object has many properties including:

u horizontal coordinate
v vertical coordinate
strength feature strength
descriptor feature descriptor (128x1)
sigma feature scale
theta feature orientation [rad]
image_id a value passed as an option to ISIFT

The SiftPointFeature object has many methods including:

plot Plot feature position
plot_scale Plot feature scale
distance Descriptor distance
match Match features
ncc Descriptor similarity

See SiftPointFeature and PointFeature classes for more details.

Notes

Reference

"Distinctive image features from scale-invariant keypoints", David G. Lowe, International Journal of Computer Vision, 60, 2 (2004), pp. 91-110.

See also

SiftPointFeature, isurf, icorner


 

© 1990-2012 Peter Corke.