.psb file support and conversion to HDf5

Hi All
I am looking for a method of importing .psb (Photoshop Big format) files. I have files from 5 to 75 gig. in size. Eventualy I would like to convert them to HDf5 file type which is a little more portable.
Tiff and Jpeg is limited to 4 gig.

Thanks,
Auch