HDF (Hierarchical Data Format) is a self-defining file format for
transfer of various types of data between different machines. The
HDF library contains interfaces for storing and retrieving compressed
or uncompressed raster images with palettes, and an interface for
storing and retrieving 
-dimensional scientific datasets together
with information about the data, such as labels, units, formats,
and ranges for all dimensions.
Version 3.3 of HDF allowed JPEG images to be included in HDF data
streams and supports the use of NetCDF. HDF allows meta-data about
Scientific Data Sets (SDSs) to be interchanged to provide details
of:
- the coordinate system used when interpreting or displaying
the data
- ranges to be used for each dimension
- labels for each dimension and the dataset as a whole
- units for each dimension and the data
- the valid maximum and minimum values for the data
- calibration information for the data
- fill or missing value information.
