Use F&H's DP style algorithm to search for global solutions to model match. More...
#include <fhs_searcher.h>
Public Member Functions | |
| fhs_searcher () | |
| Default constructor. | |
| void | set_tree (const vcl_vector< fhs_arc > &arcs, unsigned root_node) |
| Set tree defining relationships between features. | |
| void | set_geom_wt (double geom_wt) |
| Set scaling applied to shape cost (default 1.0). | |
| unsigned | root_node () const |
| Index of root node (set by last call to set_tree(). | |
| unsigned | n_points () const |
| Number of points represented. | |
| void | search (const vcl_vector< vimt_image_2d_of< float > > &feature_response) |
| Perform global search. | |
| void | points_from_root (const vgl_point_2d< double > &root_pt, vcl_vector< vgl_point_2d< double > > &pts) const |
| Compute optimal position of all points given position of root. | |
| double | best_points (vcl_vector< vgl_point_2d< double > > &pts) const |
| Compute optimal position of all points. | |
| const vimt_image_2d_of< float > & | root_cost_image () const |
| Return final total cost image for root. | |
Private Member Functions | |
| void | combine_responses (unsigned im_index, const vimt_image_2d_of< float > &feature_response) |
| Combine responses for image im_index, given supplied feature_response for that node. | |
Private Attributes | |
| vcl_vector< fhs_arc > | arc_ |
| Arcs defining neighbour relationships between features. | |
| double | geom_wt_ |
| Scaling applied to shape cost (default 1.0). | |
| vcl_vector< unsigned > | arc_to_j_ |
| arc_to_j_[j] gives index of arc ending at given j. | |
| vcl_vector< vcl_vector < unsigned > > | children_ |
| children_[i] gives list of child nodes of node i in tree. | |
| vcl_vector< vimt_image_2d_of < float > > | sum_im_ |
| Workspace for accumulated sum of responses. | |
| vcl_vector< vimt_image_2d_of < float > > | dist_im_ |
| Workspace for sum of responses, transformed by distance function. | |
| vcl_vector< vimt_image_2d_of < int > > | pos_im_ |
| pos_[i](x,y,0),pos_[i](x,y,1) is position of best response for (x,y). | |
Use F&H's DP style algorithm to search for global solutions to model match.
Model consists of a set of features, together with a tree of neighbour relationships of the form pos(j) = pos(i) + (N(mx,var_x),N(my,var_y)) where N(m,var) is a gaussian with mean m and variance var.
The aim is to find a set of points {p(i)} which minimise sum_i F_i(p(i)) + sum_k shape_cost(arc(k)) where k indexes the set of arcs defining neighbour relationships, and shape_cost(arc) = dx*dx/arc.var_x + dy*dy.var_y (dx=p(arc_j).x()-p(arc_i).x()-arc.mx) This is achieved using a combination of a quadratic distance function applied to each feature response image F(i), and a dynamic programming approach to combining the data.
Algorithm based on papers by Felzenszwalb and Huttenlocher on Pictoral Structure Matching.
Definition at line 28 of file fhs_searcher.h.
| fhs_searcher::fhs_searcher | ( | ) |
Default constructor.
Definition at line 18 of file fhs_searcher.cxx.
| double fhs_searcher::best_points | ( | vcl_vector< vgl_point_2d< double > > & | pts | ) | const |
Compute optimal position of all points.
Assumes search() has been called first Returns cost at optimal position
Assumes search() has been called first
Definition at line 247 of file fhs_searcher.cxx.
| void fhs_searcher::combine_responses | ( | unsigned | im_index, |
| const vimt_image_2d_of< float > & | feature_response | ||
| ) | [private] |
Combine responses for image im_index, given supplied feature_response for that node.
Combine responses for image im_index.
Definition at line 56 of file fhs_searcher.cxx.
| unsigned fhs_searcher::n_points | ( | ) | const [inline] |
Number of points represented.
Definition at line 75 of file fhs_searcher.h.
| void fhs_searcher::points_from_root | ( | const vgl_point_2d< double > & | root_pt, |
| vcl_vector< vgl_point_2d< double > > & | pts | ||
| ) | const |
Compute optimal position of all points given position of root.
Assumes search() has been called first
Definition at line 200 of file fhs_searcher.cxx.
| const vimt_image_2d_of< float > & fhs_searcher::root_cost_image | ( | ) | const |
Return final total cost image for root.
Definition at line 258 of file fhs_searcher.cxx.
| unsigned fhs_searcher::root_node | ( | ) | const |
Index of root node (set by last call to set_tree().
Definition at line 49 of file fhs_searcher.cxx.
| void fhs_searcher::search | ( | const vcl_vector< vimt_image_2d_of< float > > & | feature_response | ) |
Perform global search.
Images of feature response supplied. The transformation (world2im()) for each image can be used to indicate regions which don't necessarily overlap. However, effective displacements are assumed to be in pixel sized steps.
After calling search(), results can be obtained using points() and best_points() etc
| geom_wt | is the weighting applied to the geometric component of the cost. |
Images of feature response supplied. The transformation (world2im()) for each image can be used to indicate regions which don't necessarily overlap. However, effective displacements are assumed to be in pixel sized steps.
After calling search(), results can be obtained using points() and best_points() etc
Definition at line 155 of file fhs_searcher.cxx.
| void fhs_searcher::set_geom_wt | ( | double | geom_wt | ) |
Set scaling applied to shape cost (default 1.0).
Definition at line 42 of file fhs_searcher.cxx.
| void fhs_searcher::set_tree | ( | const vcl_vector< fhs_arc > & | arcs, |
| unsigned | root_node | ||
| ) |
Set tree defining relationships between features.
Input arcs define neighbour relationships in any order. root_node defines which feature to be used as the root
Definition at line 26 of file fhs_searcher.cxx.
vcl_vector<fhs_arc> fhs_searcher::arc_ [private] |
Arcs defining neighbour relationships between features.
Ordered so that parents precede children
Definition at line 33 of file fhs_searcher.h.
vcl_vector<unsigned> fhs_searcher::arc_to_j_ [private] |
arc_to_j_[j] gives index of arc ending at given j.
Definition at line 39 of file fhs_searcher.h.
vcl_vector<vcl_vector<unsigned> > fhs_searcher::children_ [private] |
children_[i] gives list of child nodes of node i in tree.
Definition at line 42 of file fhs_searcher.h.
vcl_vector<vimt_image_2d_of<float> > fhs_searcher::dist_im_ [private] |
Workspace for sum of responses, transformed by distance function.
Definition at line 48 of file fhs_searcher.h.
double fhs_searcher::geom_wt_ [private] |
Scaling applied to shape cost (default 1.0).
Definition at line 36 of file fhs_searcher.h.
vcl_vector<vimt_image_2d_of<int> > fhs_searcher::pos_im_ [private] |
pos_[i](x,y,0),pos_[i](x,y,1) is position of best response for (x,y).
Result is in image co-ordinates.
Definition at line 52 of file fhs_searcher.h.
vcl_vector<vimt_image_2d_of<float> > fhs_searcher::sum_im_ [private] |
Workspace for accumulated sum of responses.
Definition at line 45 of file fhs_searcher.h.
1.7.5.1