Digitising is the process of turning a map or diagram into a digital (vector) form - usually from a paper or scanned original.
A vector map or diagram allows re-scaling without losing detail and is extensively used in mapping, GIS, CAD and similar drawing systems when working with spatial information (both 2D and 3D).
Digitising may be achieved in several ways depending on your source material:
- Manual digitising from paper / printed maps or diagrams using a Digitising (or Graphics) tablet.
- Scanning paper / printed maps or diagrams into digital form (usually in the form of a raster image) then digitising from the image on the computer screen.
- Digital images (for example aerial or satellite images) are the primary source and are digitised as in 2 above.
- Automatic digitising from raster images – where the computer analyses the contents of the images and extracts the straight line items. Less time consuming, but possibly less discriminating, than manual digitising.
Digitising may also be used to transfer other types of data from paper to digital format. For example: a geophysical trace on continuous paper or graphs from books or other publications.
Golden Softwares’ Didger does all of the above plus has comprehensive co-ordinate (projection) conversion facilities so it is possible to produce maps of almost any projection from almost any projection system.
At GeoMEM we believe that the Didger co-ordinate conversion capabilities alone are worth the price of the software.
The other Golden Software map-based applications (Surfer and MapViewer) also offer on-screen manual digitising (items 2 and 3 listed above). These are fairly basic – but may be all you need if you have raster images to work from.
See also: Map production / mapping