'Decode boxes that are encoded relative to an anchor collection.
Args:
rel_codes: a tensor representing N relative-encoded boxes
anchors: BoxList of anchors
Returns:
boxlist: BoxList holding N boxes encoded in the ordinary way (i.e.,
with corners y_min, x_min, y_max, x_max)'

def decode(self, rel_codes, anchors):

    with tf.name_scope('Decode'):
        return self._decode(rel_codes, anchors)
