Projection of External Data
Use the following menu commands to project data in external files:
- File – Project Shape File: Project vector data in ESRI Shape files and store it in one of these formats: DXF (georeferenced), ESRI Shape (georeferenced), Adobe Illustrator AI, JPEG, PDF, PNG, SVG, or Ungenerate (georeferenced).
- File – Project Image: Project a variety of raster image formats (PNG, JPEG, GIF, TIFF, etc.). PNG is the recommended format. Projected raster images are saved in TIFF format with a .tfw world file containing the information for georeferencing the projected image.
- File – Project Grid: Project a grid in ESRI ASCII Grid format, containing a digital elevation model or other raster data, and store the projected grid in an ESRI ASCII Grid file.
Important: All data must be in the “geographic” projection (i.e. longitude / latitude or Plate Carrée projection), using degrees as units.
Raster image data with a width-to-height ratio of 2:1 is automatically georeferenced, assuming a Plate Carrée projection.
When reprojecting raster images or grid data, users have the choice between Nearest Neighbor or Bi-cubic Interpolation in the Preferences dialog. Use Nearest Neighbor for categorical data, such as thematic land cover data that should not be interpolated. Use Bi-cubic Interpolation for continuous tone images or continuous grid data, such elevation models.