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  ▸  Image Drawing  ▸  quiver◀  polygon    |    rectangle  ▶

quiver

Arguments:

  • [function_image],_sampling[%]>0,_factor>=0,_is_arrow={ 0:No | 1:Yes },_opacity,_color1,...

Description:

Draw specified 2D vector/orientation field on selected images.

Default values:

sampling=5%, factor=1, is_arrow=1, opacity=1, pattern=(undefined)


and color1=0.

Examples of use:

• Example #1

100,100,1,2,'!c?x-w/2:y-h/2' 500,500,1,3,255 quiver[-1] [-2],10

Command: 100,100,1,2,'!c?x-w/2:y-h/2' 500,500,1,3,255 quiver[-1] [-2],10
Command: 100,100,1,2,'!c?x-w/2:y-h/2' 500,500,1,3,255 quiver[-1] [-2],10

• Example #2

image.jpg +rescale2d ,600 luminance[0] gradient[0] mul[1] -1 reverse[0,1] append[0,1] c blur[0] 8 orientation[0] quiver[1] [0],20,1,1,0.8,255

Command: image.jpg +rescale2d ,600 luminance[0] gradient[0] mul[1] -1 reverse[0,1] append[0,1] c blur[0] 8 orientation[0] quiver[1] [0],20,1,1,0.8,255
Command: image.jpg +rescale2d ,600 luminance[0] gradient[0] mul[1] -1 reverse[0,1] append[0,1] c blur[0] 8 orientation[0] quiver[1] [0],20,1,1,0.8,255
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.