Projects / PROJ.4


PROJ.4 is a cartographic projections and datum shifting library written in C. It includes support for many (100+) projections, including Transverse Mercator and Lambert Conformal Conic. Included is a command line program for reprojecting points. It was originally written by Gerald Evenden of the USGS, and is in active use in various commercial and freeware software.

Operating Systems

Recent releases

  •  21 Dec 2007 20:10

    Release Notes: This release reworks pj_transform() to avoid applying ellipsoid to ellipsoid transformations as a datum shift when no datum info is available. It avoids applying "change of ellipsoid" during datum shifting based on ellipsoids getting changed to spheres for spherical projections. It has been upgraded to EPSG 6.13.

    •  23 Oct 2006 18:28

      Release Notes: EPSG was upgraded to the 6.11.1 coordinate system database. Krovak projection was fixed up, and Roussilhe Stereographic projection was added. The experimental +lon_wrapp flag was added for longitude wrapping control.

      •  30 Oct 2004 07:33

        Release Notes: JNI (Java) wrappers were added along with stereoa and geos projections. The tools are now built against PROJ DLL on Windows by default. Various fixes were made.

        •  11 May 2004 06:31

          Release Notes: Corrections were made to datum shifting and prime meridian support. An upgrade was made to the EPSG 6.5 coordinate system database.

          •  09 Jan 2002 16:25

            Release Notes: Primarily, this release fixes a serious bug with the datum shift calculations introduced in 4.4.4.


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