r.object.geometry(1grass)
| r.object.geometry(1grass) | GRASS User's Manual | r.object.geometry(1grass) |
NAME
r.object.geometry - Calculates geometry parameters for raster objects.
KEYWORDS
raster, statistics, reclass, clumps
SYNOPSIS
r.object.geometry
r.object.geometry --help
r.object.geometry [-m] input=name
[output=name] [separator=character]
format=name [--overwrite] [--help]
[--verbose] [--quiet] [--ui]
Flags:
- -m
-
Use meters as units instead of cells - --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
-
Name for output file - separator=character
-
Field separator
Special characters: pipe, comma, space, tab, newline
Default: pipe - format=name [required]
-
Output format
Options: plain, json
Default: plain
plain: Plain text output
json: JSON (JavaScript Object Notation)
DESCRIPTION
r.object.geometry calculates form statistics of raster objects in the input map and writes it to the output text file (or standard output if no output filename or ’-’ is given), with fields separated by the chosen separator. Objects are defined as clumps of adjacent cells with the same category value (e.g. output of r.clump or i.segment).
By default, values are in pixels. If values in meters is desired, the user can set the -m flag. If the current working region is in lat-long or has non-square pixels, using meters is recommended.
Statistics currently calculated are exactly the same as in v.to.db (except for compact_square and mean coordinates):
- area
- perimeter
- compact_square (compactness compared to a square: compact_square = 4 * sqrt(area) / perimeter)
- compact_circle (compactness compared to a circle: compact_circle = perimeter / ( 2 * sqrt(PI * area) ))
- fractal dimension ( fd = 2 * ( log(perimeter) / log(area + 0.001) ) )
- mean x coordinate of object (in map units)
- mean y coordinate of object (in map units)
EXAMPLE
g.region raster=soilsID r.object.geometry input=soilsID output=soils_geom.txt
The format=json option can be used to change the output
format to JSON:
r.object.geometry input=zipcodes format=json
[
{
"category": 1,
"area": 106,
"perimeter": 62,
"compact_circle": 1.6987670351864215,
"compact_square": 0.66423420264432265,
"fd": 1.7699924681225903,
"mean_x": 631382.07547169807,
"mean_y": 222764.15094339623
},
{
"category": 2,
"area": 57,
"perimeter": 36,
"compact_circle": 1.3451172460704992,
"compact_square": 0.83887049280786108,
"fd": 1.772672742164326,
"mean_x": 643460.52631578944,
"mean_y": 217232.45614035087
},
{
"category": 3,
"area": 10,
"perimeter": 16,
"compact_circle": 1.4272992929222168,
"compact_square": 0.79056941504209488,
"fd": 2.4081353865496951,
"mean_x": 631300,
"mean_y": 215450
},
{
"category": 4,
"area": 63,
"perimeter": 60,
"compact_circle": 2.1324361862292305,
"compact_square": 0.52915026221291817,
"fd": 1.9764401337147652,
"mean_x": 642345.23809523811,
"mean_y": 226599.20634920636
},
{
"category": 5,
"area": 491,
"perimeter": 156,
"compact_circle": 1.9859985189304281,
"compact_square": 0.56816717451693177,
"fd": 1.6299200778082998,
"mean_x": 637912.93279022397,
"mean_y": 220636.96537678209
},
{
"category": 6,
"area": 83,
"perimeter": 60,
"compact_circle": 1.8578355639603314,
"compact_square": 0.60736223860961991,
"fd": 1.8531256328449071,
"mean_x": 635846.38554216863,
"mean_y": 227219.8795180723
} ]
SEE ALSO
i.segment, r.clump, v.to.db
AUTHORS
Moritz Lennert
Markus Metz (diagonal clump tracing)
SOURCE CODE
Available at: r.object.geometry source code (history)
Accessed: Thursday Jun 18 12:48:03 2026
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