38 #ifndef PCL_SIFT_KEYPOINT_IMPL_H_
39 #define PCL_SIFT_KEYPOINT_IMPL_H_
41 #include <pcl/keypoints/sift_keypoint.h>
42 #include <pcl/common/io.h>
43 #include <pcl/filters/voxel_grid.h>
46 template <
typename Po
intInT,
typename Po
intOutT>
void
49 min_scale_ = min_scale;
50 nr_octaves_ = nr_octaves;
51 nr_scales_per_octave_ = nr_scales_per_octave;
56 template <
typename Po
intInT,
typename Po
intOutT>
void
59 min_contrast_ = min_contrast;
63 template <
typename Po
intInT,
typename Po
intOutT>
bool
68 PCL_ERROR (
"[pcl::%s::initCompute] : Minimum scale (%f) must be strict positive!\n",
69 name_.c_str (), min_scale_);
74 PCL_ERROR (
"[pcl::%s::initCompute] : Number of octaves (%d) must be at least 1!\n",
75 name_.c_str (), nr_octaves_);
78 if (nr_scales_per_octave_ < 1)
80 PCL_ERROR (
"[pcl::%s::initCompute] : Number of scales per octave (%d) must be at least 1!\n",
81 name_.c_str (), nr_scales_per_octave_);
84 if (min_contrast_ < 0)
86 PCL_ERROR (
"[pcl::%s::initCompute] : Minimum contrast (%f) must be non-negative!\n",
87 name_.c_str (), min_contrast_);
97 template <
typename Po
intInT,
typename Po
intOutT>
void
100 if (surface_ && surface_ != input_)
102 PCL_WARN (
"[pcl::%s::detectKeypoints] : ", name_.c_str ());
103 PCL_WARN (
"A search surface has been set by setSearchSurface, but this SIFT keypoint detection algorithm does ");
104 PCL_WARN (
"not support search surfaces other than the input cloud. ");
105 PCL_WARN (
"The cloud provided in setInputCloud is being used instead.\n");
109 scale_idx_ = pcl::getFieldIndex<PointOutT> (output,
"scale", out_fields_);
112 output.points.clear ();
119 float scale = min_scale_;
120 for (
int i_octave = 0; i_octave < nr_octaves_; ++i_octave)
123 const float s = 1.0f * scale;
127 voxel_grid.
filter (*temp);
131 const size_t min_nr_points = 25;
132 if (cloud->points.size () < min_nr_points)
136 tree_->setInputCloud (cloud);
139 detectKeypointsForOctave (*cloud, *tree_, scale, nr_scales_per_octave_, output);
146 output.width =
static_cast<uint32_t
> (output.points.size ());
151 template <
typename Po
intInT,
typename Po
intOutT>
void
153 const PointCloudIn &input,
KdTree &tree,
float base_scale,
int nr_scales_per_octave,
154 PointCloudOut &output)
157 std::vector<float> scales (nr_scales_per_octave + 3);
158 for (
int i_scale = 0; i_scale <= nr_scales_per_octave + 2; ++i_scale)
160 scales[i_scale] = base_scale * powf (2.0f, (1.0f * static_cast<float> (i_scale) - 1.0f) / static_cast<float> (nr_scales_per_octave));
162 Eigen::MatrixXf diff_of_gauss;
163 computeScaleSpace (input, tree, scales, diff_of_gauss);
166 std::vector<int> extrema_indices, extrema_scales;
167 findScaleSpaceExtrema (input, tree, diff_of_gauss, extrema_indices, extrema_scales);
169 output.points.reserve (output.points.size () + extrema_indices.size ());
171 if (scale_idx_ != -1)
174 for (
size_t i_keypoint = 0; i_keypoint < extrema_indices.size (); ++i_keypoint)
177 const int &keypoint_index = extrema_indices[i_keypoint];
179 keypoint.x = input.points[keypoint_index].x;
180 keypoint.y = input.points[keypoint_index].y;
181 keypoint.z = input.points[keypoint_index].z;
182 memcpy (reinterpret_cast<char*> (&keypoint) + out_fields_[scale_idx_].offset,
183 &scales[extrema_scales[i_keypoint]],
sizeof (
float));
184 output.points.push_back (keypoint);
190 for (
size_t i_keypoint = 0; i_keypoint < extrema_indices.size (); ++i_keypoint)
193 const int &keypoint_index = extrema_indices[i_keypoint];
195 keypoint.x = input.points[keypoint_index].x;
196 keypoint.y = input.points[keypoint_index].y;
197 keypoint.z = input.points[keypoint_index].z;
199 output.points.push_back (keypoint);
206 template <
typename Po
intInT,
typename Po
intOutT>
208 const PointCloudIn &input, KdTree &tree,
const std::vector<float> &scales,
209 Eigen::MatrixXf &diff_of_gauss)
211 diff_of_gauss.resize (input.size (), scales.size () - 1);
214 const float max_radius = 3.0f * scales.back ();
216 for (
int i_point = 0; i_point < static_cast<int> (input.size ()); ++i_point)
218 std::vector<int> nn_indices;
219 std::vector<float> nn_dist;
220 tree.radiusSearch (i_point, max_radius, nn_indices, nn_dist);
226 float filter_response = 0.0f;
227 float previous_filter_response;
228 for (
size_t i_scale = 0; i_scale < scales.size (); ++i_scale)
230 float sigma_sqr = powf (scales[i_scale], 2.0f);
232 float numerator = 0.0f;
233 float denominator = 0.0f;
234 for (
size_t i_neighbor = 0; i_neighbor < nn_indices.size (); ++i_neighbor)
236 const float &value = getFieldValue_ (input.points[nn_indices[i_neighbor]]);
237 const float &dist_sqr = nn_dist[i_neighbor];
238 if (dist_sqr <= 9*sigma_sqr)
240 float w = expf (-0.5f * dist_sqr / sigma_sqr);
241 numerator += value * w;
246 previous_filter_response = filter_response;
247 filter_response = numerator / denominator;
251 diff_of_gauss (i_point, i_scale - 1) = filter_response - previous_filter_response;
257 template <
typename Po
intInT,
typename Po
intOutT>
void
259 const PointCloudIn &input, KdTree &tree,
const Eigen::MatrixXf &diff_of_gauss,
260 std::vector<int> &extrema_indices, std::vector<int> &extrema_scales)
263 std::vector<int> nn_indices (k);
264 std::vector<float> nn_dist (k);
266 const int nr_scales =
static_cast<int> (diff_of_gauss.cols ());
267 std::vector<float> min_val (nr_scales), max_val (nr_scales);
269 for (
int i_point = 0; i_point < static_cast<int> (input.size ()); ++i_point)
272 const size_t nr_nn = tree.nearestKSearch (i_point, k, nn_indices, nn_dist);
278 for (
int i_scale = 0; i_scale < nr_scales; ++i_scale)
280 min_val[i_scale] = std::numeric_limits<float>::max ();
281 max_val[i_scale] = -std::numeric_limits<float>::max ();
283 for (
size_t i_neighbor = 0; i_neighbor < nr_nn; ++i_neighbor)
285 const float &d = diff_of_gauss (nn_indices[i_neighbor], i_scale);
287 min_val[i_scale] = (std::min) (min_val[i_scale], d);
288 max_val[i_scale] = (std::max) (max_val[i_scale], d);
293 for (
int i_scale = 1; i_scale < nr_scales - 1; ++i_scale)
295 const float &val = diff_of_gauss (i_point, i_scale);
298 if (fabs (val) >= min_contrast_)
301 if ((val == min_val[i_scale]) &&
302 (val < min_val[i_scale - 1]) &&
303 (val < min_val[i_scale + 1]))
305 extrema_indices.push_back (i_point);
306 extrema_scales.push_back (i_scale);
309 else if ((val == max_val[i_scale]) &&
310 (val > max_val[i_scale - 1]) &&
311 (val > max_val[i_scale + 1]))
313 extrema_indices.push_back (i_point);
314 extrema_scales.push_back (i_scale);
321 #define PCL_INSTANTIATE_SIFTKeypoint(T,U) template class PCL_EXPORTS pcl::SIFTKeypoint<T,U>;
323 #endif // #ifndef PCL_SIFT_KEYPOINT_IMPL_H_