G'MIC - GREYC's Magic for Image Computing: A Full-Featured Open-Source Framework for Image Processing
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A Full-Featured Open-Source Framework for Image Processing

Latest stable version: 3.5.5        Current pre-release: 3.6.0 (2025/08/04)

Reference
Table of Contents  ▸  List of Commands  ▸  Mathematical Operators  ▸  sub◀  sqrt    |    tan  ▶

sub

Built-in command

Arguments:

  • value[%]    or
  • [image]    or
  • 'formula'    or
  • (no arg)

Description:

Subtract specified value, image or mathematical expression to selected images, or compute the pointwise difference of selected images.

(equivalent to shortcut command -).

Examples of use:

• Example #1

image.jpg +sub 30% cut 0,255

Command: image.jpg +sub 30% cut 0,255
Command: image.jpg +sub 30% cut 0,255

• Example #2

image.jpg +mirror x sub[-1] [0]

Command: image.jpg +mirror x sub[-1] [0]
Command: image.jpg +mirror x sub[-1] [0]

• Example #3

image.jpg sub 'i(w/2+0.9*(x-w/2),y)'

Command: image.jpg sub 'i(w/2+0.9*(x-w/2),y)'

• Example #4

image.jpg +mirror x sub

Command: image.jpg +mirror x sub
G'MIC - GREYC's Magic for Image Computing: A Full-Featured Open-Source Framework for Image Processing

G'MIC is an open-source software distributed under the CeCILL free software licenses (LGPL-like and/or
GPL-compatible). Copyrights (C) Since July 2008, David Tschumperlé - GREYC UMR CNRS 6072, Image Team.