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

A Full-Featured Open-Source Framework for Image Processing



Latest stable version: 3.1.5

Reference

Table of Contents  ▸  List of Commands  ▸  Blending and Fading  ▸  sub_alpha◀  fade_z    |    animate  ▶

sub_alpha

Arguments:

Description:

Compute the minimal alpha-channel difference (opposite of alpha blending) between the selected images

and the specified base image.
The alpha difference A-B is defined as the image having minimal opacity, such that alpha_blend(B,A-B) = A.

Default values:

opacity_gain=1.

Example of use:

$ gmic image.jpg testimage2d {w},{h} +sub_alpha[0] [1] display_rgba

Command: image.jpg testimage2d {w},{h} +sub_alpha[0] [1] display_rgba
Command: image.jpg testimage2d {w},{h} +sub_alpha[0] [1] display_rgba
Command: image.jpg testimage2d {w},{h} +sub_alpha[0] [1] display_rgba
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.