[MINC-development] large attributes in MINC2 and upgrading to HDF5 version 1.8

[Vladimir S. FONOV]

Hello Everybody,

I came across a problem in MINC2 , that total size of attributes for 
group was limited to 64k , which was creating problems in storing some 
dicom tags, for example dicom_0x0029:el_0x1020 is sometimes quite big, 
so together with other tags it would overfill 64k limit and cause problems.

The problem didn't happen with MINC1 which didn't seem to have this 
limitation.

The solution for this problem is explained in 
http://www.hdfgroup.org/HDF5/doc/UG/13_Attributes.html , see "Large 
Attributes Stored in Dense Attribute Storage ". Unfortunately it creates 
a minc file which requires one to use HDF5 version 1.8 , so potentially 
files with such large attributes will not be readable by minc compiled 
with HDF5 version 1.6 ( minc 2.0, I suppose).

I made changes and also created a couple of new test cases in 
HDF5_large_attribute  branch of libminc: 
https://github.com/BIC-MNI/libminc/tree/HDF5_large_attribute


Unless there are some objections, I will merge it into the develop 
branch of libminc (which is supposed to become libminc release 2.3.00 
sometime soon).

-- 
Best regards,

  Vladimir S. FONOV ~ vladimir.fonov <at> gmail.com