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                                           //
  16 // (C) Idiap Research Institute                                          //
  17 //                                                                       //
  18 // Contact <francois.fleuret@idiap.ch> for comments & bug reports        //
  19 ///////////////////////////////////////////////////////////////////////////
  20
  21 #include "labelled_image_pool_file.h"
  22
  23 LabelledImagePoolFile::LabelledImagePoolFile(char *file_name) {
  24   _stream = new ifstream(file_name);
  25
  26   if(_stream->fail()) {
  27     cerr << "Can not open image pool " << file_name << " for reading." << endl;
  28     exit(1);
  29   }
  30
  31   cout << "Opening image pool " << file_name << " ... ";
  32   cout.flush();
  33
  34   LabelledImage dummy;
  35
  36   int nb_image_max = 1024;
  37   int nb_targets = 0;
  38
  39   _nb_images = 0;
  40   streampos *tmp_positions = new streampos[nb_image_max];
  41
  42   // This looks slightly ugly to me
  43
  44   _stream->seekg(0, ios::end);
  45   streampos end = _stream->tellg();
  46   _stream->seekg(0, ios::beg);
  47
  48   while(_stream->tellg() < end) {
  49     grow(&nb_image_max, _nb_images, &tmp_positions, 2);
  50     tmp_positions[_nb_images] = _stream->tellg();
  51     dummy.read(_stream);
  52     nb_targets += dummy.nb_targets();
  53     _nb_images++;
  54   }
  55
  56   _images = new LabelledImage *[_nb_images];
  57   _image_stream_positions = new streampos[_nb_images];
  58   _image_nb_refs = new int[_nb_images];
  59
  60   for(int i = 0; i < _nb_images; i++) {
  61     _images[i] = 0;
  62     _image_stream_positions[i] = tmp_positions[i];
  63     _image_nb_refs[i] = 0;
  64   }
  65
  66   delete[] tmp_positions;
  67
  68   cout << "done." << endl;
  69   cout << "It contains " << _nb_images << " images and " << nb_targets << " targets." << endl;
  70 }
  71
  72 LabelledImagePoolFile::~LabelledImagePoolFile() {
  73 #ifdef DEBUG
  74   for(int i = 0; i < _nb_images; i++) if(_image_nb_refs[i] > 0) {
  75     cerr << "Destroying a pool while images are grabbed." << endl;
  76     abort();
  77   }
  78 #endif
  79   delete[] _images;
  80   delete[] _image_stream_positions;
  81   delete[] _image_nb_refs;
  82   delete _stream;
  83 }
  84
  85 int LabelledImagePoolFile::nb_images() {
  86   return _nb_images;
  87 }
  88
  89 LabelledImage *LabelledImagePoolFile::grab_image(int n_image) {
  90   if(_image_nb_refs[n_image] == 0) {
  91     _stream->seekg(_image_stream_positions[n_image]);
  92     _images[n_image] = new LabelledImage();
  93     _images[n_image]->read(_stream);
  94   }
  95   _image_nb_refs[n_image]++;
  96   return _images[n_image];
  97 }
  98
  99 void LabelledImagePoolFile::release_image(int n_image) {
 100   ASSERT(_image_nb_refs[n_image] > 0);
 101   _image_nb_refs[n_image]--;
 102   if(_image_nb_refs[n_image] <= 0) delete _images[n_image];
 103 }