wxGUI Raster Digitizer

KEYWORDS

       display, GUI, raster, editing, digitizer

DESCRIPTION

       Raster Digitizer is a simple tool to quickly to draw lines, areas, and circles and save these features in
       a raster map.  It is accessible from Map Display toolbar (from the combo box on the right).

       Raster Digitizer currently allows you to:

           •   draw polygons, lines and points

           •   set category value of the feature you are drawing

           •   set feature width (width of currently digitized line or diameter of  a  digitized  point  in  map
               units)

           •   create a new raster from scratch or from an already existing raster

           •   undo edits and save edits before leaving the digitizer

       The typical workflow includes these steps:

       1      Set computational region as needed.

       2      Switch to Raster Digitizer and select a map to create.  Select either a new raster or create a new
              raster from existing raster, also select raster type (CELL, FCELL, DCELL)

       3      Specify category value and width before drawing a feature

       4      Specify digitizing tool (area, line, point)

       5      Start digitizing and when you want to finish area or line, use right click

       6      Change color of temporary overlay depending on your needs

       7      Set different category and repeat

       8      At any point you can use Undo or Save

       9      If existing raster is used for the new raster, digitized areas will respect the color  table,  but
              you can always set different color table.

NOTES

       Raster Digitizer respects computational region including the currently set resolution.

EXAMPLES

       In  the  following  figures  we start with elev_lid792_1m raster map in North carolina sample dataset and
       digitize two buildings, one rectangular and one with circular footprint.  Both buildings  have  the  roof
       level  at  130  m.  We set the width when digitizing the point to 50 meters which results in the building
       having 50 m in diameter.  When we are done with digitizing, we save the result and explore  cast  shadows
       of the buildings with r.sun module:
       g.region raster=elev_lid792_1m
       # now create elev_edited raster by digitizing and save
       r.slope.aspect elevation=elev_edited slope=elev_slope aspect=elev_aspect
       r.sun elevation=elev_edited aspect=elev_aspect slope=elev_slope beam_rad=beam day=172 time=6
       Figure: Steps to digitize new buildings on elev_lid792_1m raster map.

SEE ALSO

        wxGUI
       wxGUI components,
       r.in.poly (backend of digitizer),
       g.gui.vdigit

AUTHOR

       Anna Petrasova, NCSU GeoForALL Laboratory

SOURCE CODE

       Available at: wxGUI Raster Digitizer source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual