'Return the roidb indices for the next minibatch.'

def _get_next_minibatch_inds(self):

    if cfg.TRAIN.HAS_RPN:
        if ((self._cur + cfg.TRAIN.IMS_PER_BATCH) >= len(self._roidb)):
            self._shuffle_roidb_inds()
        db_inds = self._perm[self._cur:(self._cur + cfg.TRAIN.IMS_PER_BATCH)]
        self._cur += cfg.TRAIN.IMS_PER_BATCH
    else:
        db_inds = np.zeros(cfg.TRAIN.IMS_PER_BATCH, dtype=np.int32)
        i = 0
        while (i < cfg.TRAIN.IMS_PER_BATCH):
            ind = self._perm[self._cur]
            num_objs = self._roidb[ind]['boxes'].shape[0]
            if (num_objs != 0):
                db_inds[i] = ind
                i += 1
            self._cur += 1
            if (self._cur >= len(self._roidb)):
                self._shuffle_roidb_inds()
    return db_inds
