examples/OpenCV/siftDetector/hess/sift.h File Reference#include "cxcore.h"
Go to the source code of this file.
Detailed Description
Functions for detecting SIFT image features.
For more information, refer to:
Lowe, D. Distinctive image features from scale-invariant keypoints. International Journal of Computer Vision, 60, 2 (2004), pp.91--110.
Copyright (C) 2006-2007 Rob Hess <hess@eecs.oregonstate.edu>
Note: The SIFT algorithm is patented in the United States and cannot be used in commercial products without a license from the University of British Columbia. For more information, refer to the file LICENSE.ubc that accompanied this distribution.
- Version:
- 1.1.1-20070913
Definition in file sift.h.
Define Documentation
#define SIFT_CONTR_THR 0.04 |
default threshold on keypoint ratio of principle curvatures
Definition at line 55 of file sift.h.
Referenced by sift_features().
#define SIFT_DESCR_HIST_BINS 8 |
default number of bins per histogram in descriptor array
Definition at line 64 of file sift.h.
Referenced by sift_features().
#define SIFT_DESCR_WIDTH 4 |
double image size before pyramid construction?
Definition at line 58 of file sift.h.
Referenced by sift_features().
default number of sampled intervals per octave
Definition at line 46 of file sift.h.
Referenced by sift_features().
Function Documentation
int _sift_features |
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IplImage * |
img, |
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struct feature ** |
feat, |
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int |
intvls, |
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double |
sigma, |
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double |
contr_thr, |
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int |
curv_thr, |
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int |
img_dbl, |
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int |
descr_width, |
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int |
descr_hist_bins | |
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) |
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Finda SIFT features in an image using user-specified parameter values. All detected features are stored in the array pointed to by feat.
- Parameters:
-
| img | the image in which to detect features |
| feat | a pointer to an array in which to store detected features |
| intvls | the number of intervals sampled per octave of scale space |
| sigma | the amount of Gaussian smoothing applied to each image level before building the scale space representation for an octave |
| contr_thr | a threshold on the value of the scale space function , where is a vector specifying feature location and scale, used to reject unstable features; assumes pixel values in the range [0, 1] |
| curv_thr | threshold on a feature's ratio of principle curvatures used to reject features that are too edge-like |
| img_dbl | should be 1 if image doubling prior to scale space construction is desired or 0 if not |
| descr_width | the width, , of the array of orientation histograms used to compute a feature's descriptor |
| descr_hist_bins | the number of orientations in each of the histograms in the array used to compute a feature's descriptor |
- Returns:
- Returns the number of keypoints stored in feat or -1 on failure
- See also:
- sift_features()
Finds SIFT features in an image using user-specified parameter values. All detected features are stored in the array pointed to by feat.
- Parameters:
-
| img | the image in which to detect features |
| fea | a pointer to an array in which to store detected features |
| intvls | the number of intervals sampled per octave of scale space |
| sigma | the amount of Gaussian smoothing applied to each image level before building the scale space representation for an octave |
| cont_thr | a threshold on the value of the scale space function , where is a vector specifying feature location and scale, used to reject unstable features; assumes pixel values in the range [0, 1] |
| curv_thr | threshold on a feature's ratio of principle curvatures used to reject features that are too edge-like |
| img_dbl | should be 1 if image doubling prior to scale space construction is desired or 0 if not |
| descr_width | the width, , of the array of orientation histograms used to compute a feature's descriptor |
| descr_hist_bins | the number of orientations in each of the histograms in the array used to compute a feature's descriptor |
- Returns:
- Returns the number of keypoints stored in feat or -1 on failure
- See also:
- sift_keypoints()
Definition at line 109 of file sift.cpp.
int sift_features |
( |
IplImage * |
img, |
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struct feature ** |
feat | |
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) |
| | |
Finds SIFT features in an image using default parameter values. All detected features are stored in the array pointed to by feat.
- Parameters:
-
| img | the image in which to detect features |
| feat | a pointer to an array in which to store detected features |
- Returns:
- Returns the number of features stored in feat or -1 on failure
- See also:
- _sift_features()
Definition at line 75 of file sift.cpp.
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