labelled_image_pool_file.cc

   1
   2 ///////////////////////////////////////////////////////////////////////////
   3 // This program is free software: you can redistribute it and/or modify  //
   4 // it under the terms of the version 3 of the GNU General Public License //
   5 // as published by the Free Software Foundation.                         //
   6 //                                                                       //
   7 // This program is distributed in the hope that it will be useful, but   //
   8 // WITHOUT ANY WARRANTY; without even the implied warranty of            //
   9 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      //
  10 // General Public License for more details.                              //
  11 //                                                                       //
  12 // You should have received a copy of the GNU General Public License     //
  13 // along with this program. If not, see <http://www.gnu.org/licenses/>.  //
  14 //                                                                       //
  15 // Written by Francois Fleuret, (C) IDIAP                                //
  16 // Contact <francois.fleuret@idiap.ch> for comments & bug reports        //
  17 ///////////////////////////////////////////////////////////////////////////
  18
  19 #include "labelled_image_pool_file.h"
  20
  21 LabelledImagePoolFile::LabelledImagePoolFile(char *file_name) {
  22   _stream = new ifstream(file_name);
  23
  24   if(_stream->fail()) {
  25     cerr << "Can not open image pool " << file_name << " for reading." << endl;
  26     exit(1);
  27   }
  28
  29   cout << "Opening image pool " << file_name << " ... ";
  30   cout.flush();
  31
  32   LabelledImage dummy;
  33
  34   int nb_image_max = 1024;
  35   int nb_targets = 0;
  36
  37   _nb_images = 0;
  38   streampos *tmp_positions = new streampos[nb_image_max];
  39
  40   // This looks slightly ugly to me
  41
  42   _stream->seekg(0, ios::end);
  43   streampos end = _stream->tellg();
  44   _stream->seekg(0, ios::beg);
  45
  46   while(_stream->tellg() < end) {
  47     grow(&nb_image_max, _nb_images, &tmp_positions, 2);
  48     tmp_positions[_nb_images] = _stream->tellg();
  49     dummy.read(_stream);
  50     nb_targets += dummy.nb_targets();
  51     _nb_images++;
  52   }
  53
  54   _images = new LabelledImage *[_nb_images];
  55   _image_stream_positions = new streampos[_nb_images];
  56   _image_nb_refs = new int[_nb_images];
  57
  58   for(int i = 0; i < _nb_images; i++) {
  59     _images[i] = 0;
  60     _image_stream_positions[i] = tmp_positions[i];
  61     _image_nb_refs[i] = 0;
  62   }
  63
  64   delete[] tmp_positions;
  65
  66   cout << "done." << endl;
  67   cout << "It contains " << _nb_images << " images and " << nb_targets << " targets." << endl;
  68 }
  69
  70 LabelledImagePoolFile::~LabelledImagePoolFile() {
  71 #ifdef DEBUG
  72   for(int i = 0; i < _nb_images; i++) if(_image_nb_refs[i] > 0) {
  73     cerr << "Destroying a pool while images are grabbed." << endl;
  74     abort();
  75   }
  76 #endif
  77   delete[] _images;
  78   delete[] _image_stream_positions;
  79   delete[] _image_nb_refs;
  80   delete _stream;
  81 }
  82
  83 int LabelledImagePoolFile::nb_images() {
  84   return _nb_images;
  85 }
  86
  87 LabelledImage *LabelledImagePoolFile::grab_image(int n_image) {
  88   if(_image_nb_refs[n_image] == 0) {
  89     _stream->seekg(_image_stream_positions[n_image]);
  90     _images[n_image] = new LabelledImage();
  91     _images[n_image]->read(_stream);
  92   }
  93   _image_nb_refs[n_image]++;
  94   return _images[n_image];
  95 }
  96
  97 void LabelledImagePoolFile::release_image(int n_image) {
  98   ASSERT(_image_nb_refs[n_image] > 0);
  99   _image_nb_refs[n_image]--;
 100   if(_image_nb_refs[n_image] <= 0) delete _images[n_image];
 101 }