i.ortho.transform(1grass)

💖 i.ortho.transform 💖

okay so bestie, this is the GRASS User's Manual page for i.ortho.transform, and it's lowkey iconic. It computes a coordinate transformation based on the control points. That's the whole vibe. Let's get into it 🦋

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🌸 NAME 🌸

i.ortho.transform — computes a coordinate transformation based on the control points. periodt 💅

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🎀 KEYWORDS 🎀

imagery, orthorectify, transformation, GCP ✨

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🌈 SYNOPSIS 🌈

i.ortho.transform
i.ortho.transform --help
i.ortho.transform [-srxp] group=name  [format=string[,string,...]]
[coords=name]   [--help]  [--verbose]  [--quiet]  [--ui]

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👑 FLAGS 👑

• -s — display summary information 💖
• -r — reverse transform of coords file or coeff. dump. Target east,north,height coordinates go to local x,y,z 🔄
• -x — display transform matrix coefficients 🧮
• -p — enable panorama camera correction 📸
• --help — print usage summary 🫶
• --verbose — verbose module output (she's chatty, we love her) 💬
• --quiet — quiet module output 🤫
• --ui — force launching GUI dialog 🖥️

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🍓 PARAMETERS 🍓

• group=name [required] — name of input imagery group. yeah you literally have to give her this one, no cap ⭐
• 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) ⚠️
• coords=name — file containing coordinates to transform ("-" to read from stdin). Local x,y,z coordinates to target east,north,height 🌍

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✨ DESCRIPTION ✨

i.ortho.transform is an utility to compute transformation based upon GCPs and output error measurements. it's giving "the math girlie who also files your taxes" fr fr 💅

If coordinates are given with the input file option or fed from stdin, both the input and the output format is "x y z" with one coordinate pair per line. Reverse transform is performed with the -r flag. 🔄

The format option determines how control points are printed out. A summary on the control points can be printed with the -s flag. The summary includes maximum deviation observed when transforming GCPs and overall RMS. The format option is ignored when coordinates are given with the input file option. 🚨 (yes bestie, ignored — don't fight her on this)

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🧚 NOTES 🧚

Ortho-transformation is a 2-step transformation. First, source coordinates are transformed to sensor coordinates, then sensor coordinates are transformed to target coordinates. two steps, no shortcuts, she's thorough like that 💖

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💜 SEE ALSO 💜

i.rectify

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🙈 TODO 🙈

Update this document with x,y,z<->E,N,H information

(not me leaving a TODO in the manpage 😭 she said "soon" and never came back)

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🌟 AUTHORS 🌟

• Brian J. Buckley
• Glynn Clements
• Hamish Bowman

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🔥 SOURCE CODE 🔥

Available at: i.ortho.transform source code (history) 📜

Latest change: Thursday May 08 14:35:40 2025 in commit: 9528b1e38ba37992c1597a979dc3efbb07b74ec5

Main index | Imagery index | Topics index | Keywords index | Graphical index | Full index 🗂️

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k that's the whole page bestie, you ate 💅

and for the cute sign-off: this beautiful thing is © 2003-2026 GRASS Development Team, and it's the GRASS 8.5.0 Reference Manual — GRASS 8.5.0, run don't walk 🏃‍♀️💨 ✨🦋🎀