This package contains Java code to read and write VICAR and PDS image files, and read ISIS image files. It is a software library intended for use with applications rather than a standalone package, but a SimpleConvert program exists as a test/demo.

Formats Supported

There are 3 different methods of access to the image data available in the library. All three formats are popular in the planetary science community.

1. VICAR (Video Image Communication And Retrieval) is a general purpose image processing system developed continuously since 1966 by the Multimission Image Processing Lab (MIPL) at JPL. Its primary use is to process images from JPL's unmanned planetary spacecraft, such as MER, Cassini, MSL, Galileo, Voyager, and many others. It is still in active use today.

   http://www-mipl.jpl.nasa.gov/vicar.html

2. PDS (Planetary Data System) is the standard NASA archive format used for data from all planetary missions. PDS is actually a collection of many different formats; the subset supported here is the PDS3 uncompressed image data format.

   http://pds.jpl.nasa.gov

3. ISIS (Integrated Software for Imagers and Spectrometers) is an image processing system developed by the USGS (U.S. Geological Survey) for use with planetary mission data.

   http://isis.astrogeology.usgs.gov

Access Methods

• Image I/O Plugin

  The Image I/O (IIO) package has been part of the Java core since version 1.4. It consists of a format-neutral software architechture with a series of "plugins" that implement reading and writing for specific image file formats.

  Plugins are the recommended method of using this package. The package contains reader plugins for VICAR, PDS, and ISIS, and writer plugins for VICAR and PDS. The package also contains IIO "transcoders" for VICAR->PDS and PDS->VICAR, which convert metadata (image labels) from one format to another.

• JAI Codec

  The Java Advanced Imaging (JAI) package, from Sun (now Oracle), contains a "codec" (coder/decoder) mechanism that is very similar to the Image I/O Plugin system. This package contains reader and writer codecs for VICAR and PDS. The JAI codecs predate IIO plugins and were in fact a model for implementing the IIO plugins. While the JAI codecs are not formally deprecated, they should not be used with new code. Use the IIO Plugins instead.

• Low-level I/O package

  The third access level is a low-level I/O package, which both the plugins and codecs use. This package is more of a traditional image I/O system, with procedure-based calls (in an object-oriented framework) to read and write lines, tiles, and metadata items. The low-level package is primarily designed for VICAR format, but the supported PDS and ISIS format subsets are similar enough that it is also used for them.