What is in the HDF4 library?
HDF currently supports several data structure types: Scientific Datasets (multi-dimensional arrays), vdatas (binary tables), "general" raster images, text entries (annotations), 8-bit raster images, 24-bit raster images, and color palettes.
HDF contains: the base library, the multi-file (SDS) library, the jpeg library, and the gzip library. HDF library functions can be called from C or FORTRAN user application programs.
The base library contains a general purpose interface and application level interfaces, one for each data structure type. Each application level interface is specifically designed to read, write and manipulate one type. The general purpose interface contains functions, such as file I/O, error handling, memory management and physical storage.
The multi-file (SDS) library integrates the netCDF model with HDF Scientific data sets, and supports simultaneous access to multiple files and multiple objects. This part is referred to as the mfhdf library in the rest of this FAQ.
The jpeg and gzip libraries allow you to use jpeg and gzip compression for those application programming interfaces that support them.