Dear members of the CIFTI working group:

In the brain imaging community we have had a strong resistance to adopting HDF5 as the underlying format for our data. This is the case, even though this format is readily readable and writable by C++, Python, R, Matlab, Java and others, and has been extensively used by communities that generate a lot of data. Furthermore, this format allows extensive structured metadata to be stored in the header, serializable compression of datasets and parallel access to datasets even under compression. Such a format would allow web services to return queries on subsets of the data without having to ship the entire dataset.

The benefits of having native readers/writers in high level languages would make it significantly easier to play with the Connectome project data in CIFTI format, relative to currently being able to work primarily using the connectome workbench.

Now there are many other solutions to the technical problem of storing scientific data, but it seems HDF5 might be one that has been reasonably well tested in large data domains.

I would encourage the working group to consider the option, and if they already have and decided not to use it, at least to inform the community as to why HDF5 is not applicable to the problem of storing brain imaging data.