One of the new features that is coming with the next gvSIG version 2.3 is the capability to read and write PRJ files that was, without any doubt, one of the most requested features by the user community and that will bring considerable advantages.
What is a PRJ?
It is a file that is associated with an information layer (shapefile, raster …) and contains information related to layer coordinate reference system.
If we open a PRJ file with a text editor, variables will be shown in capital letters while values or specifications will be into brackets.
PRJ file information are shown as a single line unformatted text, it is up to different applications to translate and interpret the values contained in the file.
As stated before, starting from gvSIG 2.3, the application will be able to interpret this type of file and automatically identifies the layer projection. In the same way, when a layer is created or exported, the PRJ file is automatically generated.
Let’s have a look to this video showing how projection is automatically detected when loading a couple of layers. In the first case the layer has the same projection system of the View and thus it is added as it is. In the second case, due to its different reference system, gvSIG identifies this difference and automatically performs a reprojection to the View EPSG reference system.