3 * mtp is the ``Multi Tracked Paths'', an implementation of the
4 * k-shortest paths algorithm for multi-target tracking.
6 * Copyright (c) 2012 Idiap Research Institute, http://www.idiap.ch/
7 * Written by Francois Fleuret <francois.fleuret@idiap.ch>
9 * This file is part of mtp.
11 * mtp is free software: you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License version 3 as
13 * published by the Free Software Foundation.
15 * mtp is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
18 * License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with selector. If not, see <http://www.gnu.org/licenses/>.
25 #include "mtp_tracker.h"
31 void MTPTracker::free() {
32 delete[] _edge_lengths;
34 deallocate_array<scalar_t>(detection_scores);
35 deallocate_array<int>(allowed_motion);
40 void MTPTracker::allocate(int t, int l) {
46 detection_scores = allocate_array<scalar_t>(nb_time_steps, nb_locations);
47 allowed_motion = allocate_array<int>(nb_locations, nb_locations);
49 entrances = new int[nb_locations];
50 exits = new int[nb_locations];
52 for(int l = 0; l < nb_locations; l++) {
55 for(int m = 0; m < nb_locations; m++) {
56 allowed_motion[l][m] = 0;
60 for(int t = 0; t < nb_time_steps; t++) {
61 for(int l = 0; l < nb_locations; l++) {
62 detection_scores[t][l] = 0.0;
70 void MTPTracker::write(ostream *os) {
71 (*os) << nb_locations << " " << nb_time_steps <<endl;
75 for(int l = 0; l < nb_locations; l++) {
76 for(int m = 0; m < nb_locations; m++) {
77 (*os) << allowed_motion[l][m];
78 if(m < nb_locations - 1) (*os) << " "; else (*os) << endl;
84 for(int l = 0; l < nb_locations; l++) {
85 (*os) << entrances[l];
86 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
91 for(int l = 0; l < nb_locations; l++) {
93 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
98 for(int t = 0; t < nb_time_steps; t++) {
99 for(int l = 0; l < nb_locations; l++) {
100 (*os) << detection_scores[t][l];
101 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
106 void MTPTracker::read(istream *is) {
113 for(int l = 0; l < nb_locations; l++) {
114 for(int m = 0; m < nb_locations; m++) {
115 (*is) >> allowed_motion[l][m];
119 for(int l = 0; l < nb_locations; l++) {
120 (*is) >> entrances[l];
123 for(int l = 0; l < nb_locations; l++) {
127 for(int t = 0; t < nb_time_steps; t++) {
128 for(int l = 0; l < nb_locations; l++) {
129 (*is) >> detection_scores[t][l];
134 void MTPTracker::write_trajectories(ostream *os) {
135 (*os) << nb_trajectories() << endl;
136 for(int t = 0; t < nb_trajectories(); t++) {
138 << " " << trajectory_entrance_time(t)
139 << " " << trajectory_duration(t)
140 << " " << trajectory_score(t);
141 for(int u = 0; u < trajectory_duration(t); u++) {
142 (*os) << " " << trajectory_location(t, u);
148 MTPTracker::MTPTracker() {
152 detection_scores = 0;
162 MTPTracker::~MTPTracker() {
163 delete[] _edge_lengths;
165 deallocate_array<scalar_t>(detection_scores);
166 deallocate_array<int>(allowed_motion);
171 int MTPTracker::early_pair_node(int t, int l) {
172 return 1 + (2 * t + 0) * nb_locations + l;
175 int MTPTracker::late_pair_node(int t, int l) {
176 return 1 + (2 * t + 1) * nb_locations + l;
179 void MTPTracker::build_graph() {
180 // Delete the existing graph if there was one
181 delete[] _edge_lengths;
184 int nb_motions = 0, nb_exits = 0, nb_entrances = 0;
186 for(int l = 0; l < nb_locations; l++) {
187 if(exits[l]) nb_exits++;
188 if(entrances[l]) nb_entrances++;
189 for(int m = 0; m < nb_locations; m++) {
190 if(allowed_motion[l][m]) nb_motions++;
194 int nb_vertices = 2 + 2 * nb_time_steps * nb_locations;
197 // The edges from the source to the first frame, and from the last
200 // The edges from the source to the entrances and from the exits
201 // to the sink (in every time frames but the first for the
202 // entrances, and last for the exits)
203 (nb_time_steps - 1) * (nb_exits + nb_entrances) +
204 // The edges for the motions, between every successive frames
205 (nb_time_steps - 1) * nb_motions +
206 // The edges inside the duplicated nodes
207 nb_locations * nb_time_steps;
209 int *node_from = new int[nb_edges];
210 int *node_to = new int[nb_edges];
212 int source = 0, sink = nb_vertices - 1;
215 _edge_lengths = new scalar_t[nb_edges];
217 // We put the in-node edges first, since these are the ones whose
218 // lengths we will have to change before tracking, according to the
221 for(int t = 0; t < nb_time_steps; t++) {
222 for(int l = 0; l < nb_locations; l++) {
223 node_from[e] = early_pair_node(t, l);
224 node_to[e] = late_pair_node(t, l);
229 // The edges from the source to the first time frame
231 for(int l = 0; l < nb_locations; l++) {
232 node_from[e] = source;
233 node_to[e] = 1 + l + 0 * nb_locations;
234 _edge_lengths[e] = 0.0;
238 // The edges from the last frame to the sink
240 for(int l = 0; l < nb_locations; l++) {
241 node_from[e] = late_pair_node(nb_time_steps - 1, l);
243 _edge_lengths[e] = 0.0;
247 // The edges between frames, corresponding to allowed motions
249 for(int t = 0; t < nb_time_steps - 1; t++) {
250 for(int l = 0; l < nb_locations; l++) {
251 for(int k = 0; k < nb_locations; k++) {
252 if(allowed_motion[l][k]) {
253 node_from[e] = late_pair_node(t, l);
254 node_to[e] = early_pair_node(t+1, k);
255 _edge_lengths[e] = 0.0;
262 // The edges from the source to the entrances, and from the exits to
265 for(int t = 0; t < nb_time_steps; t++) {
266 for(int l = 0; l < nb_locations; l++) {
267 if(t > 0 && entrances[l]) {
268 node_from[e] = source;
269 node_to[e] = early_pair_node(t, l);
270 _edge_lengths[e] = 0.0;
273 if(t < nb_time_steps - 1 && exits[l]) {
274 node_from[e] = late_pair_node(t, l);
276 _edge_lengths[e] = 0.0;
282 // We are done, build the graph
284 _graph = new MTPGraph(nb_vertices, nb_edges,
292 void MTPTracker::print_graph_dot(ostream *os) {
294 for(int t = 0; t < nb_time_steps; t++) {
295 for(int l = 0; l < nb_locations; l++) {
296 _edge_lengths[e++] = - detection_scores[t][l];
299 _graph->print_dot(os);
302 void MTPTracker::track() {
306 for(int t = 0; t < nb_time_steps; t++) {
307 for(int l = 0; l < nb_locations; l++) {
308 _edge_lengths[e++] = - detection_scores[t][l];
312 _graph->find_best_paths(_edge_lengths);
313 _graph->retrieve_disjoint_paths();
316 for(int p = 0; p < _graph->nb_paths; p++) {
317 Path *path = _graph->paths[p];
318 cout << "PATH " << p << " [length " << path->nb_nodes << "] " << path->nodes[0];
319 for(int n = 1; n < path->nb_nodes; n++) {
320 cout << " -> " << path->nodes[n];
327 int MTPTracker::nb_trajectories() {
328 return _graph->nb_paths;
331 scalar_t MTPTracker::trajectory_score(int k) {
332 return -_graph->paths[k]->length;
335 int MTPTracker::trajectory_entrance_time(int k) {
336 return (_graph->paths[k]->nodes[1] - 1) / (2 * nb_locations);
339 int MTPTracker::trajectory_duration(int k) {
340 return (_graph->paths[k]->nb_nodes - 2) / 2;
343 int MTPTracker::trajectory_location(int k, int time_from_entry) {
344 return (_graph->paths[k]->nodes[2 * time_from_entry + 1] - 1) % nb_locations;