def get_training_roidb(imdb):
    """Returns a roidb (Region of Interest database) for use in training."""
    if cfg.TRAIN.USE_FLIPPED:
      print('Appending horizontally-flipped training examples...')
      imdb.append_flipped_images()
      print('done')

    print('Preparing training data...')

    prepare_roidb(imdb)
    #ratio_index = rank_roidb_ratio(imdb)
    print('done')

    return imdb.roidb
Returns a roidb (Region of Interest database) for use in training.
lib/roi_data_layer/roidb.py