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_motions);
36 deallocate_array<int>(exits);
37 deallocate_array<int>(entrances);
40 void MTPTracker::allocate(int t, int l) {
46 detection_scores = allocate_array<scalar_t>(nb_time_steps, nb_locations);
47 allowed_motions = allocate_array<int>(nb_locations, nb_locations);
49 entrances = allocate_array<int>(nb_time_steps, nb_locations);
50 exits = allocate_array<int>(nb_time_steps, nb_locations);
52 for(int l = 0; l < nb_locations; l++) {
53 for(int m = 0; m < nb_locations; m++) {
54 allowed_motions[l][m] = 0;
58 for(int t = 0; t < nb_time_steps; t++) {
59 for(int l = 0; l < nb_locations; l++) {
60 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_motions[l][m];
78 if(m < nb_locations - 1) (*os) << " "; else (*os) << endl;
84 for(int t = 0; t < nb_time_steps; t++) {
85 for(int l = 0; l < nb_locations; l++) {
86 (*os) << entrances[t][l];
87 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
93 for(int t = 0; t < nb_time_steps; t++) {
94 for(int l = 0; l < nb_locations; l++) {
96 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
102 for(int t = 0; t < nb_time_steps; t++) {
103 for(int l = 0; l < nb_locations; l++) {
104 (*os) << detection_scores[t][l];
105 if(l < nb_locations - 1) (*os) << " "; else (*os) << endl;
110 void MTPTracker::read(istream *is) {
117 for(int l = 0; l < nb_locations; l++) {
118 for(int m = 0; m < nb_locations; m++) {
119 (*is) >> allowed_motions[l][m];
123 for(int t = 0; t < nb_time_steps; t++) {
124 for(int l = 0; l < nb_locations; l++) {
125 (*is) >> entrances[t][l];
129 for(int t = 0; t < nb_time_steps; t++) {
130 for(int l = 0; l < nb_locations; l++) {
131 (*is) >> exits[t][l];
135 for(int t = 0; t < nb_time_steps; t++) {
136 for(int l = 0; l < nb_locations; l++) {
137 (*is) >> detection_scores[t][l];
142 void MTPTracker::write_trajectories(ostream *os) {
143 (*os) << nb_trajectories() << endl;
144 for(int t = 0; t < nb_trajectories(); t++) {
146 << " " << trajectory_entrance_time(t)
147 << " " << trajectory_duration(t)
148 << " " << trajectory_score(t);
149 for(int u = 0; u < trajectory_duration(t); u++) {
150 (*os) << " " << trajectory_location(t, u);
156 MTPTracker::MTPTracker() {
160 detection_scores = 0;
170 MTPTracker::~MTPTracker() {
174 int MTPTracker::early_pair_node(int t, int l) {
175 return 1 + (2 * t + 0) * nb_locations + l;
178 int MTPTracker::late_pair_node(int t, int l) {
179 return 1 + (2 * t + 1) * nb_locations + l;
182 void MTPTracker::build_graph() {
183 // Delete the existing graph if there was one
184 delete[] _edge_lengths;
187 int nb_motions = 0, nb_exits = 0, nb_entrances = 0;
189 for(int l = 0; l < nb_locations; l++) {
190 for(int t = 0; t < nb_time_steps; t++) {
191 if(exits[t][l]) nb_exits++;
192 if(entrances[t][l]) nb_entrances++;
194 for(int m = 0; m < nb_locations; m++) {
195 if(allowed_motions[l][m]) nb_motions++;
199 int nb_vertices = 2 + 2 * nb_time_steps * nb_locations;
202 // The edges from the source to the entrances and from the exits
204 nb_exits + nb_entrances +
205 // The edges for the motions, between every successive frames
206 (nb_time_steps - 1) * nb_motions +
207 // The edges inside the duplicated nodes
208 nb_locations * nb_time_steps;
210 int *node_from = new int[nb_edges];
211 int *node_to = new int[nb_edges];
213 int source = 0, sink = nb_vertices - 1;
216 _edge_lengths = new scalar_t[nb_edges];
218 // We put the in-node edges first, since these are the ones whose
219 // lengths we will have to change before tracking, according to the
222 for(int t = 0; t < nb_time_steps; t++) {
223 for(int l = 0; l < nb_locations; l++) {
224 node_from[e] = early_pair_node(t, l);
225 node_to[e] = late_pair_node(t, l);
230 // The edges between frames, corresponding to allowed motions
232 for(int t = 0; t < nb_time_steps - 1; t++) {
233 for(int l = 0; l < nb_locations; l++) {
234 for(int k = 0; k < nb_locations; k++) {
235 if(allowed_motions[l][k]) {
236 node_from[e] = late_pair_node(t, l);
237 node_to[e] = early_pair_node(t+1, k);
238 _edge_lengths[e] = 0.0;
245 // The edges from the source to the entrances, and from the exits to
248 for(int t = 0; t < nb_time_steps; t++) {
249 for(int l = 0; l < nb_locations; l++) {
250 if(entrances[t][l]) {
251 node_from[e] = source;
252 node_to[e] = early_pair_node(t, l);
253 _edge_lengths[e] = 0.0;
257 node_from[e] = late_pair_node(t, l);
259 _edge_lengths[e] = 0.0;
265 // We are done, build the graph
267 _graph = new MTPGraph(nb_vertices, nb_edges,
275 void MTPTracker::print_graph_dot(ostream *os) {
277 for(int t = 0; t < nb_time_steps; t++) {
278 for(int l = 0; l < nb_locations; l++) {
279 _edge_lengths[e++] = - detection_scores[t][l];
282 _graph->print_dot(os);
285 void MTPTracker::track() {
289 for(int t = 0; t < nb_time_steps; t++) {
290 for(int l = 0; l < nb_locations; l++) {
291 _edge_lengths[e++] = - detection_scores[t][l];
295 _graph->find_best_paths(_edge_lengths);
296 _graph->retrieve_disjoint_paths();
299 for(int p = 0; p < _graph->nb_paths; p++) {
300 Path *path = _graph->paths[p];
301 cout << "PATH " << p << " [length " << path->nb_nodes << "] " << path->nodes[0];
302 for(int n = 1; n < path->nb_nodes; n++) {
303 cout << " -> " << path->nodes[n];
310 int MTPTracker::nb_trajectories() {
311 return _graph->nb_paths;
314 scalar_t MTPTracker::trajectory_score(int k) {
315 return -_graph->paths[k]->length;
318 int MTPTracker::trajectory_entrance_time(int k) {
319 return (_graph->paths[k]->nodes[1] - 1) / (2 * nb_locations);
322 int MTPTracker::trajectory_duration(int k) {
323 return (_graph->paths[k]->nb_nodes - 2) / 2;
326 int MTPTracker::trajectory_location(int k, int time_from_entry) {
327 return (_graph->paths[k]->nodes[2 * time_from_entry + 1] - 1) % nb_locations;