NAME

       r.resamp.interp  - Resamples raster map layers to a finer grid using interpolation.

KEYWORDS

       raster, resample

SYNOPSIS

       r.resamp.interp
       r.resamp.interp help
       r.resamp.interp input=name output=name  [method=string]   [--overwrite]  [--verbose]  [--quiet]

   Flags:
       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Name of input raster map

       output=name
           Name for output raster map

       method=string
           Interpolation method
           Options: nearest,bilinear,bicubic
           Default: bilinear

DESCRIPTION

       r.resamp.interp  resamples  an  input  raster  map  by  interpolating between the neighboring cells via a
       selectable resampling algorithm. All cells present in the neighborhood of the input raster cell  must  be
       non-null to generate a non-null cell in the output raster map. A choice of three interpolation methods is
       available;  each  uses  the  weighted  values of a different number of adjacent cells in the input map to
       determine the value of each cell in the output map as follows:

                     nearest neighbour (1 cell)

                     bilinear (4 cells)

                     bicubic (16 cells)
       This module is intended for reinterpolation of continuous data to a different resolution rather than  for
       interpolation from scattered data (use the v.surf.* modules for that purpose).

NOTES

       Resampling  modules (r.resample, r.resamp.stats, r.resamp.interp, r.resamp.rst) resample the map to match
       the current region settings.

       Note that for bilinear and bicubic interpolation, cells of the output raster that cannot  be  bounded  by
       the  appropriate number of input cell centers are set to NULL (NULL propagation). This could occur due to
       the input cells being outside the current region, being NULL or MASKed.

       For longitude-latitude locations, the interpolation algorithm is based on degree fractions,  not  on  the
       absolute distances between cell centers.  Any attempt to implement the latter would violate the integrity
       of the interpolation method.

EXAMPLE

       Resample elevation raster map to a higher resolution (from 500m to 250m; North Carolina sample dataset):
       g.region rast=elev_state_500m -p
       g.region res=250 -ap
       r.resamp.interp input=elev_state_500m output=elev_state_250m

SEE ALSO

       g.region, r.resample, r.resamp.rst r.resamp.stats

AUTHOR

       Glynn Clements

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                              r.resamp.interp(1grass)