- FITS?
The standard data format used in astronomy
Stands for 'Flexible Image Transport System'
Endorsed by NASA and the International Astronomical Union
Much more than just another image format (such as JPEG or GIF)
Used for the transport, analysis, and archival storage of scientific data sets
Multi-dimensional arrays: 1D spectra, 2D images, 3D+ data cubes
Tables containing rows and columns of information
Header keywords provide descriptive information about the data
See also the descriptions on the Wikipedia and Library of Congress Web sites.
wgs) is a standard for cartography, geodesy, and navigation, which comprises the Earth's standard coordinate system. As wekk as a standard sheroidal reference surface (the datum or reference ellipsoid) for raw altitude data, and a gravitational equipotential sufrace (the geoid) that defines the nominal sea level.
wgs was last done in 1984 (hence, wgs 1984; EPSG:4326), and revised in 2004; previously wgs flavors included wgs 72, wgs 66, and wgs 60.
wgs is the Reference Coordinate System used by the Global Positioning System
World Geodetic System
World Geodetic System
WGS_84_reference_frame.pngvia Wikimedia Commons
NetCDF
Network Common Data Form (NetCDF) is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data.
NetCDF can be found on the Unidata program's servers. at the University Corporation for Atmospheric Research (ucr).
NetCDF is an open standard, and both NetCDF Classic and 64-bit Offset Format are international standards at the Open Geospatial Consortium
NetCDF come with .nc and/or .cdf file extensions.
NetCDF started permitting the use of HD5F data file format (2008, v 4.0), and added support for both Fortran and C client access to specified subsets of remote data via OPeNDAP.
hdf can comein an variety of flavors: .hdf, .h4, .hdf4, .he2, .h5, .hdf5, .he5.
Hierarchical Data Format (HDF, HDF4, or HDF5) is the name of a set of file formats and libraries designed to store and organize large amounts of numerical data. Orginally developed at the National Center for Supercomputing Applications, it is currently supported by the non-profit hdf Group, whose mission is to ensure continued development of hdf5 technologies, and the continued accessibility of data currently stored in hdf5.
Hiearchical Data Format
The hdf Group
http://www.unidata.ucar.edu/software/netcdf/">Network Common Data Form (NetCDF)
NetCDF is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data.
OPeNDAP, an acronym for "Open-source Project for a Network Data Access Protocol", is a data transport architecture and protocol widely used by earth scientists. The protocol is based on HTTP and the current specification is OPeNDAP 2.0 draft. OPeNDAP includes standards for encapsulating structured data, annotating the data with attributes and adding semantics that describe the data. The protocol is maintained by OPeNDAP.org, a publicly funded non-profit organization that also provides free reference implementations of OPeNDAP servers and clients.
An OPeNDAP client could be an ordinary browser, although this gives limited functionality. Usually, an OPeNDAP client is a graphics program (like GrADS, Ferret or ncBrowse) or web application (like DChart) linked with an OPeNDAP library.
An OPeNDAP client sends requests to an OPeNDAP server, and receives various types of documents or binary data as a response. One such document is called a DDS (received when a DDS request is sent), that describes the structure of a data set. A data set, seen from the server side, may be a file, a collection of files or a database. Another document type that may be received is DAS, which gives attribute values on the fields described in the DDS. Binary data is received when the client sends a DODS request.
An OPeNDAP server can serve an arbitrarily large collection of data. Data on the server is often in HDF or NetCDF format, but can be in any format including a user-defined format. Compared to ordinary file transfer protocols (e.g. FTP), a major advantage using OPeNDAP is the ability to retrieve subsets of files, and also the ability to aggregate data from several files in one transfer operation.
OPeNDAP is widely used by governmental agencies such as NASA and NOAA to serve satellite, weather and other observed earth science data.
OpenEXR is an open-source high-dynamic-range floating-point image file format for high-quality image processing and storage.
OpenEXR is used by ILM on all motion pictures currently in production. The first movies to employ OpenEXR were Harry Potter and the Sorcerers Stone, Men in Black II, Gangs of New York, and Signs. Since then, OpenEXR has become ILM's main image file format.
OpenEXR 's features include:
- Higher dynamic range and color precision than existing 8- and 10-bit image file formats
- Support for 16-bit floating-point, 32-bit floating-point, and 32-bit integer pixels. The 16-bit floating-point format, called "half", is compatible with the half data type in NVIDIA's Cg graphics language and is supported natively on their new GeForce FX and Quadro FX 3D graphics solutions
- Multiple image compression algorithms, both lossless and lossy. Some of the included codecs can achieve 2:1 lossless compression ratios on images with film grain. The lossy codecs have been tuned for visual quality and decoding performance
- Extensibility. New compression codecs and image types can easily be added by extending the C++ classes included in the OpenEXR software distribution. New image attributes (strings, vectors, integers, etc.) can be added to OpenEXR image headers without affecting backward compatibility with existing OpenEXR applications
- Deep Data. Pixels can store a variable length list of samples. The main rationale behind deep-images is to store multiple values at different depths for each pixel. Support for hard surface and volumetric representation requirements for deep compositing workflows
- Multi-part image files. Files can contain a number of separate, but related, images in one file. Access to any part is independent of the others; in particular, no access of data need take place for unrequested parts
ILM has released OpenEXR as free software. The OpenEXR software distribution includes:
IlmImf, a library that reads and writes OpenEXR images.
IlmImfUtil, a convenience library to simplify development of OpenEXR utilities.
Half, a C++ class for manipulating half values as if they were a built-in C++ data type.
Imath, a math library with support for matrices, 2d- and 3d-transformations, solvers for linear/quadratic/cubic equations, and more.
exrdisplay, a sample application for viewing OpenEXR images on a display at various exposure settings.
OpenEXR's software distribution is licensed under the modified BSD license.
References and Resources
