def rpn_roidb(self, gt_roidb, append_gt=False):
        """
        get rpn roidb and ground truth roidb
        :param gt_roidb: ground truth roidb
        :param append_gt: append ground truth
        :return: roidb of rpn
        """
        if append_gt:
            print 'appending ground truth annotations'
            rpn_roidb = self.load_rpn_roidb(gt_roidb)
            roidb = IMDB.merge_roidbs(gt_roidb, rpn_roidb)
        else:
            roidb = self.load_rpn_roidb(gt_roidb)
        return roidb

        get rpn roidb and ground truth roidb
        :param gt_roidb: ground truth roidb
        :param append_gt: append ground truth
        :return: roidb of rpn
        
lib/dataset/imdb.py