Proj4J

Proj4J is a Java port of the popular PROJ.4 Cartographic Projection library.
Proj4J is hosted under the MetaCRS project at OSGeo. See the Proj4J home page for full details. This page is a summary of the information there.

Wagner VII Projection

Design Goals

Rely on PROJ.4 for the definition of all projection and datum conversion algorithms
Maintain compatibility with PROJ.4 for
- the coordinate system specification language
- resources such as the database of coordinate systems, datum conversion grids, etc
Software design follows well-established Java patterns and best practices
Software architecture is as simple as possible and easily maintainable
100% pure Java (no native code)
Target platform is Java 1.5 (with a high degree of 1.4 compatibility)
Execution is efficient for performing bulk coordinate transformations
Support datum transformations
Support as many PROJ.4 parameters as possible
Error handling is via well-documented Java exceptions
High quality, informative Javadoc
Provide a set of unit tests to validate the API functions
Support the emerging MetaCRS Common Test Format database
Provide additional tools such as:
- A GUI to create, inspect and execute Coordinate System definitions
- A GUI to visualize projections on the globe

Currently Out of Scope

The following features are not currently in scope. They could be added if development resources and interest are available.

Support for mappings to other Coordinate System representations and authorities (e.g. OGC WKT, various spatial database formats, etc.)

Development

The Proj4J SVN repository is currently hosted at the OSGeo Proj4J site: http://svn.osgeo.org/metacrs/proj4j

History

The Proj4J codebase is based on a partial port of PROJ.4 carried out by JHLabs circa 2006. This port provided a large number of the PROJ.4 projections, but did not support some PROJ.4 features such as datum transformation.

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