1r.resamp.interp(1) GRASS GIS User's Manual r.resamp.interp(1)
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6 r.resamp.interp - Resamples raster map to a finer grid using interpo‐
7 lation.
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10 raster, resample, interpolation, nearest neighbor, bilinear, bicubic,
11 lanczos
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14 r.resamp.interp
15 r.resamp.interp --help
16 r.resamp.interp input=name output=name [method=string] [--overwrite]
17 [--help] [--verbose] [--quiet] [--ui]
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19 Flags:
20 --overwrite
21 Allow output files to overwrite existing files
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23 --help
24 Print usage summary
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26 --verbose
27 Verbose module output
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29 --quiet
30 Quiet module output
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32 --ui
33 Force launching GUI dialog
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35 Parameters:
36 input=name [required]
37 Name of input raster map
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39 output=name [required]
40 Name for output raster map
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42 method=string
43 Sampling interpolation method
44 Options: nearest, bilinear, bicubic, lanczos
45 Default: bilinear
46 nearest: Nearest-neighbor interpolation
47 bilinear: Bilinear interpolation
48 bicubic: Bicubic interpolation
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51 r.resamp.interp resamples an input raster map by interpolating between
52 the neighboring cells via a selectable resampling algorithm. All cells
53 present in the neighborhood of the input raster cell must be non-null
54 to generate a non-null cell in the output raster map. A choice of four
55 interpolation methods is available; each uses the weighted values of a
56 different number of adjacent cells in the input map to determine the
57 value of each cell in the output map as follows:
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59 • nearest neighbour (1 cell)
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61 • bilinear (4 cells)
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63 • bicubic (16 cells)
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65 • lanczos (25 cells)
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67 This module is intended for reinterpolation of continuous data to a
68 different resolution rather than for interpolation from scattered data
69 (use the v.surf.* modules for that purpose).
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72 Resampling modules (r.resample, r.resamp.stats, r.resamp.interp, r.re‐
73 samp.rst) resample the map to match the current region settings.
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75 Note that for bilinear, bicubic and lanczos interpolation, cells of the
76 output raster that cannot be bounded by the appropriate number of input
77 cell centers are set to NULL (NULL propagation). This could occur due
78 to the input cells being outside the current region, being NULL or
79 MASKed.
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81 For longitude-latitude locations, the interpolation algorithm is based
82 on degree fractions, not on the absolute distances between cell cen‐
83 ters. Any attempt to implement the latter would violate the integrity
84 of the interpolation method.
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87 Resample elevation raster map to a higher resolution (from 500m to
88 250m; North Carolina sample dataset):
89 g.region raster=elev_state_500m -p
90 g.region res=250 -ap
91 r.resamp.interp input=elev_state_500m output=elev_state_250m \
92 method=bilinear
93 Original 500m resolution elevation map
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95 Resampled (bilinear) 250m resolution elevation map
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98 g.region, r.resample, r.resamp.filter, r.resamp.rst, r.resamp.stats
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100 Overview: Interpolation and Resampling in GRASS GIS
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103 Glynn Clements
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106 Available at: r.resamp.interp source code (history)
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108 Accessed: Saturday Jan 21 21:15:06 2023
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110 Main index | Raster index | Topics index | Keywords index | Graphical
111 index | Full index
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113 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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117GRASS 8.2.1 r.resamp.interp(1)