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SIFT image descriptor patch
From: |
Etienne Grossmann |
Subject: |
SIFT image descriptor patch |
Date: |
Tue, 27 Dec 2005 11:32:33 -0500 |
User-agent: |
Mutt/1.4.2.1i |
Hi All,
this patch could be of interest to octave users who do image
processing. You can apply it to the matlab code in siftDemoV4 [1] to
allow octave to extract SIFT image features [2] with David Lowe's
package.
The SIFT image detector identifies interest points, somewhat like a
corner detector does, and gives them a local descriptor. The
descriptor can then be used for matching purposes (another way to
perform matching could be correlation of a small window around the
feature). Wrt to corners + local window correlation, SIFT features are
more robust to changes in illumination and viewpoint [3] and they are
increasingly used in computer vision.
The siftDemo has functions to find sift features and to perform
matching. I've tested the patch under octave+linux, matlab+linux (it
works) and octave+win (it fails, probs w/ imagemagick + double).
Hth,
Etienne
[1] http://www.cs.ubc.ca/spider/lowe/keypoints/siftDemoV4.zip
Synopsis:
unzip siftDemoV4.zip;
cd siftDemoV4;
patch -p1 < mySift.patch
In octave, make sure sift.m is in your path, then
>> [image, descriptors, locs] =
sift("/home/etienne/prog/various/siftDemoV4/book.pgm");
>> showkeys(image, locs)
See also 'help match'
[2] http://www.cs.ubc.ca/~lowe/keypoints/
David G. Lowe, Öbject recognition from local scale-invariant
features," International Conference on Computer Vision, Corfu,
Greece (September 1999), pp. 1150-1157.
[3] A performance evaluation of local descriptors Krystian
Mikolajczyk, Cordelia Schmid International Conference on Computer
Vision & Pattern Recognition - June 2003
http://lear.inrialpes.fr/pubs/2003/MS03/mikolajczyk_cvpr2003.pdf
--
Etienne Grossmann ------ http://www.cs.uky.edu/~etienne
mySift.patch
Description: Text document
- SIFT image descriptor patch,
Etienne Grossmann <=