NAME

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

KEYWORDS

       raster, resample, interpolation, nearest neighbor, bilinear, bicubic, lanczos

SYNOPSIS

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

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

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name [required]
           Name of input raster map

       output=name [required]
           Name for output raster map

       method=string
           Sampling interpolation method
           Options: nearest, bilinear, bicubic, lanczos
           Default: bilinear
           nearest: Nearest-neighbor interpolation
           bilinear: Bilinear interpolation
           bicubic: Bicubic interpolation

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 four 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)

           •   lanczos (25 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,  bicubic  and lanczos 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 raster=elev_state_500m -p
       g.region res=250 -ap
       r.resamp.interp input=elev_state_500m output=elev_state_250m \
                       method=bilinear
       Original 500m resolution elevation map

       Resampled (bilinear) 250m resolution elevation map

SEE ALSO

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

       Overview: Interpolation and Resampling in GRASS GIS

AUTHOR

       Glynn Clements

SOURCE CODE

       Available at: r.resamp.interp source code (history)

       Accessed: unknown

       Main index | Raster index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2022 GRASS Development Team, GRASS GIS 7.8.7 Reference Manual

GRASS 7.8.7                                                                              r.resamp.interp(1grass)