SIFTKeypoint detects the Scale Invariant Feature Transform keypoints for a given point cloud dataset containing points and intensity. This implementation adapts the original algorithm from images to point clouds. For more information about the image-based SIFT interest operator, see: More...
#include <sift_keypoint.h>
Public Types | |
| typedef Keypoint< PointInT, PointOutT >::KdTree | KdTree |
| typedef Keypoint< PointInT, PointOutT >::PointCloudIn | PointCloudIn |
| typedef Keypoint< PointInT, PointOutT >::PointCloudOut | PointCloudOut |
Public Member Functions | |
| void | setMinimumContrast (float min_contrast) |
| Provide a threshold to limit detection of keypoints without sufficient contrast. | |
| void | setScales (float min_scale, int nr_octaves, int nr_scales_per_octave) |
| Specify the range of scales over which to search for keypoints. | |
| SIFTKeypoint () | |
| Empty constructor. | |
Protected Member Functions | |
| void | detectKeypoints (PointCloudOut &output) |
| Detect the SIFT keypoints for a set of points given in setInputCloud () using the spatial locator in setSearchMethod (). | |
Private Member Functions | |
| void | computeScaleSpace (const PointCloudIn &input, KdTree &tree, const std::vector< float > &scales, Eigen::MatrixXf &diff_of_gauss) |
| Compute the difference-of-Gaussian (DoG) scale space for the given input and scales. | |
| void | detectKeypointsForOctave (const PointCloudIn &input, KdTree &tree, float base_scale, int nr_scales_per_octave, PointCloudOut &output) |
| Detect the SIFT keypoints for a given point cloud for a single octave. | |
| void | findScaleSpaceExtrema (const PointCloudIn &input, KdTree &tree, const Eigen::MatrixXf &diff_of_gauss, std::vector< int > &extrema_indices, std::vector< int > &extrema_scales) |
| Find the local minima and maxima in the provided difference-of-Gaussian (DoG) scale space. | |
Private Attributes | |
| float | min_contrast_ |
| The minimum contrast required for detection. | |
| float | min_scale_ |
| The standard deviation of the smallest scale in the scale space. | |
| int | nr_octaves_ |
| The number of octaves (i.e. doublings of scale) over which to search for keypoints. | |
| int | nr_scales_per_octave_ |
| The number of scales to be computed for each octave. | |
SIFTKeypoint detects the Scale Invariant Feature Transform keypoints for a given point cloud dataset containing points and intensity. This implementation adapts the original algorithm from images to point clouds. For more information about the image-based SIFT interest operator, see:
David G. Lowe, "Distinctive image features from scale-invariant keypoints," International Journal of Computer Vision, 60, 2 (2004), pp. 91-110.
Definition at line 55 of file sift_keypoint.h.
| typedef Keypoint<PointInT, PointOutT>::KdTree pcl::SIFTKeypoint< PointInT, PointOutT >::KdTree |
Reimplemented from pcl::Keypoint< PointInT, PointOutT >.
Definition at line 60 of file sift_keypoint.h.
| typedef Keypoint<PointInT, PointOutT>::PointCloudIn pcl::SIFTKeypoint< PointInT, PointOutT >::PointCloudIn |
Reimplemented from pcl::Keypoint< PointInT, PointOutT >.
Definition at line 58 of file sift_keypoint.h.
| typedef Keypoint<PointInT, PointOutT>::PointCloudOut pcl::SIFTKeypoint< PointInT, PointOutT >::PointCloudOut |
Reimplemented from pcl::Keypoint< PointInT, PointOutT >.
Definition at line 59 of file sift_keypoint.h.
| pcl::SIFTKeypoint< PointInT, PointOutT >::SIFTKeypoint | ( | ) | [inline] |
Empty constructor.
Definition at line 69 of file sift_keypoint.h.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::computeScaleSpace | ( | const PointCloudIn & | input, | |
| KdTree & | tree, | |||
| const std::vector< float > & | scales, | |||
| Eigen::MatrixXf & | diff_of_gauss | |||
| ) | [inline, private] |
Compute the difference-of-Gaussian (DoG) scale space for the given input and scales.
| input | the point cloud for which the DoG scale space will be computed | |
| tree | a k-D tree of the points in input | |
| scales | a vector containing the scales over which to compute the DoG scale space | |
| diff_of_gauss | the resultant DoG scale space (in a number-of-points by number-of-scales matrix) |
Definition at line 163 of file sift_keypoint.hpp.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::detectKeypoints | ( | PointCloudOut & | output | ) | [inline, protected, virtual] |
Detect the SIFT keypoints for a set of points given in setInputCloud () using the spatial locator in setSearchMethod ().
| output | the resultant cloud of keypoints |
Implements pcl::Keypoint< PointInT, PointOutT >.
Definition at line 78 of file sift_keypoint.hpp.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::detectKeypointsForOctave | ( | const PointCloudIn & | input, | |
| KdTree & | tree, | |||
| float | base_scale, | |||
| int | nr_scales_per_octave, | |||
| PointCloudOut & | output | |||
| ) | [inline, private] |
Detect the SIFT keypoints for a given point cloud for a single octave.
| input | the point cloud to detect keypoints in | |
| tree | a k-D tree of the points in input | |
| base_scale | the first (smallest) scale in the octave | |
| nr_scales_per_octave | the number of scales to to compute | |
| output | the resultant point cloud containing the SIFT keypoints |
Definition at line 128 of file sift_keypoint.hpp.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::findScaleSpaceExtrema | ( | const PointCloudIn & | input, | |
| KdTree & | tree, | |||
| const Eigen::MatrixXf & | diff_of_gauss, | |||
| std::vector< int > & | extrema_indices, | |||
| std::vector< int > & | extrema_scales | |||
| ) | [inline, private] |
Find the local minima and maxima in the provided difference-of-Gaussian (DoG) scale space.
| input | the input point cloud | |
| tree | a k-D tree of the points in input | |
| diff_of_gauss | the DoG scale space (in a number-of-points by number-of-scales matrix) | |
| extrema_indices | the resultant vector containing the point indices of each keypoint | |
| extrema_scales | the resultant vector containing the scale indices of each keypoint |
Definition at line 217 of file sift_keypoint.hpp.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::setMinimumContrast | ( | float | min_contrast | ) | [inline] |
Provide a threshold to limit detection of keypoints without sufficient contrast.
| min_contrast | the minimum contrast required for detection |
Definition at line 66 of file sift_keypoint.hpp.
| void pcl::SIFTKeypoint< PointInT, PointOutT >::setScales | ( | float | min_scale, | |
| int | nr_octaves, | |||
| int | nr_scales_per_octave | |||
| ) | [inline] |
Specify the range of scales over which to search for keypoints.
| min_scale | the standard deviation of the smallest scale in the scale space | |
| nr_octaves | the number of octaves (i.e. doublings of scale) to compute | |
| nr_scales_per_octave | the number of scales to compute within each octave |
Definition at line 37 of file sift_keypoint.hpp.
float pcl::SIFTKeypoint< PointInT, PointOutT >::min_contrast_ [private] |
The minimum contrast required for detection.
Definition at line 138 of file sift_keypoint.h.
float pcl::SIFTKeypoint< PointInT, PointOutT >::min_scale_ [private] |
The standard deviation of the smallest scale in the scale space.
Definition at line 129 of file sift_keypoint.h.
int pcl::SIFTKeypoint< PointInT, PointOutT >::nr_octaves_ [private] |
The number of octaves (i.e. doublings of scale) over which to search for keypoints.
Definition at line 132 of file sift_keypoint.h.
int pcl::SIFTKeypoint< PointInT, PointOutT >::nr_scales_per_octave_ [private] |
The number of scales to be computed for each octave.
Definition at line 135 of file sift_keypoint.h.
