Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
Updated manual page: here
NAME
m.transform - Computes a coordinate transformation based on the control points.
KEYWORDS
miscellaneous,
transformation,
GCP
SYNOPSIS
m.transform
m.transform --help
m.transform [-srx] group=name order=integer [format=string[,string,...]] [input=name] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -s
- Display summary information
- -r
- Reverse transform of coords file or coeff. dump
- Target east,north coordinates to local x,y
- -x
- Display transform matrix coefficients
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- group=name [required]
- Name of input imagery group
- order=integer [required]
- Rectification polynomial order
- Options: 1-3
- format=string[,string,...]
- Output format
- Options: idx, src, dst, fwd, rev, fxy, rxy, fd, rd
- Default: fd,rd
- idx: point index
- src: source coordinates
- dst: destination coordinates
- fwd: forward coordinates (destination)
- rev: reverse coordinates (source)
- fxy: forward coordinates difference (destination)
- rxy: reverse coordinates difference (source)
- fd: forward error (destination)
- rd: reverse error (source)
- input=name
- File containing coordinates to transform ("-" to read from stdin)
- Local x,y coordinates to target east,north
m.transform is an utility to compute transformation
based upon GCPs and output error measurements.
For coordinates given with the
input file option or fed from
stdin, the input format is "x y" with one coordinate pair per
line.
The transformations are:
order=1:
e = [E0 E1][1].[1]
[E2 0][e] [n]
n = [N0 N1][1].[1]
[N2 0][e] [n]
order=2:
e = [E0 E1 E3][1 ] [1 ]
[E2 E4 0][e ].[n ]
[E5 0 0][e²] [n²]
n = [N0 N1 N3][1 ] [1 ]
[N2 N4 0][e ].[n ]
[N5 0 0][e²] [n²]
order=3:
e = [E0 E1 E3 E6][1 ] [1 ]
[E2 E4 E7 0][e ].[n ]
[E5 E8 0 0][e²] [n²]
[E9 0 0 0][e³] [n³]
n = [N0 N1 N3 N6][1 ] [1 ]
[N2 N4 N7 0][e ].[n ]
[N5 N8 0 0][e²] [n²]
[N9 0 0 0][e³] [n³]
["." = dot-product, (AE).N = N'EA.]
In other words, order=1 and order=2 are equivalent to order=3 with
the higher coefficients equal to zero.
i.rectify,
v.rectify,
v.transform
Brian J. Buckley
Glynn Clements
Hamish Bowman
Last changed: $Date: 2014-11-28 07:43:22 -0800 (Fri, 28 Nov 2014) $
SOURCE CODE
Available at: m.transform source code (history)
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
Updated manual page: here
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© 2003-2019
GRASS Development Team,
GRASS GIS 7.2.4svn Reference Manual