What is an H4 file?
An H4 or HDF4 is one of the Hierarchical Data Formats (HDF) and is used to store large amount of data. It is an open source file format that supports storing complex heterogeneous data. HDF4 is an older data format as compared to the HDF5. HDF file formats are maintained and published by the HDF group, a non-profit organization. HDF files also support storage of metadata to completely represent the stored data.
Brief History of HDF File Format
The formulation of Hierarchical Data Formats was initiated in 1987 by the Graphics Foundations Task Force (GFTF). During this time, several different file formats were proposed for standardization of single format. NASA selected HDF as the standard method for storing and serving scientific data.
HDF4 File Format
H4 files are saved in “file Directory” like structure as per the HDF file format specifications. These specifications define the overall structure of HDF files for storage on disc but without users worrying about the underlying file structure.
Application areas of H4 files include aerospace, physics, engineering, finance, academic research, genomics, astronomy, electronics instruments, and medical fields.
HDF4 Data Model
HDF4 or H4 file is like a container that consists of heterogeneous data objects. The type of datasets supported by H4 files include:
- Images
- Tables
- Text elements
- Graphs
- Documents such as PDF and Excel documents
H4 File Viewer
The HDF group provides HDFView software that consists of the HDFView utility and the Java HDF Object Package.