How to read <HDF5 object reference> in python

I was trying to read the HDF5 file and don’t know how to read the HDF5 object reference

>>> bb= h5py.File('SUNRGBD2Dseg.mat', 'r')
>>> bb['SUNRGBD2Dseg']['seglabel']
<HDF5 dataset "seglabel": shape (10335, 1), type "|O">
>>> bb['SUNRGBD2Dseg']['seglabel'][0]
array([<HDF5 object reference>], dtype=object)

Actually, the following code works

>>> bb['SUNRGBD2Dseg']['seglabel']
<HDF5 dataset "seglabel": shape (10335, 1), type "|O">
>>> ref = bb['SUNRGBD2Dseg']['seglabel'][0][0]
>>> res = np.array(bb[ref])
>>> res.shape
(730, 530)

Reference

https://stackoverflow.com/questions/28541847/how-convert-this-type-of-data-hdf5-object-reference-to-something-more-readable