Fred's ImageMagick Scripts



    Licensing:

    Copyright © Fred Weinhaus

    My scripts are available free of charge for non-commercial use, ONLY.

    For use of my scripts in commercial (for-profit) environments or non-free applications, please contact me (Fred Weinhaus) for licensing arrangements. My email address is fmw at alink dot net.

    If you: 1) redistribute, 2) incorporate any of these scripts into other free applications or 3) reprogram them in another scripting language, then you must contact me for permission, especially if the result might be used in a commercial or for-profit environment.

    Usage, whether stated or not in the script, is restricted to the above licensing arrangements. It is also subject, in a subordinate manner, to the ImageMagick license, which can be found at: http://www.imagemagick.org/script/license.php

EDGES


Applies edge extraction to image.

Download Script

last modified: April 25, 2015



USAGE: edges [-w width ] [-b brightness] [-s smoothing] [-g] infile outfile
USAGE: edges [-h or -help]

-w ... width ........ width of edges; integer>0; default=2
-b ... brightness ... brightening of edges; float>=0; default=5
-s ... smoothing .... pre-smoothing of the image to filter small edges;
..................... float>=0; default=1
-g .................. convert image to grayscale before getting edges

PURPOSE: To apply edge extraction to image.

DESCRIPTION: EdGES applies edge extraction to image. The user may control any or all of the width, brightness and/or smoothing arguments. This script is similar to the Photoshop Glowing Edges filter.

ARGUMENTS:

-w width ... WIDTh width of extracted edges. Values are integers>0. The default=2.

-b brightness ... BRIGHTNESS of edges. Values are floats>=0. The default=5.

-s smoothing ... SMOOTHING of the input image to filter out small edges. Values are floast>=0. The default=1.

-g ... converts the input image to GRAYSCALE before extracting edges.

REQUIREMENTS: IM 6.5.9.3 is required due to the use of -morphology edgeout.

CAVEAT: No guarantee that this script will work on all platforms, nor that trapping of inconsistent parameters is complete and foolproof. Use At Your Own Risk.


EXAMPLES


Example 1 -- Variation in Width

Original

Arguments:
-w 1 -b 5 -s 1

Arguments:
-w 2 -b 5 -s 1

Arguments:
-w 3 -b 5 -s 1



Example 2 -- Variation in Brightness

Original

Arguments:
-w 2 -b 3 -s 1

Arguments:
-w 2 -b 5 -s 1

Arguments:
-w 2 -b 7 -s 1



Example 3 -- Variation in Smoothing

Original

Arguments:
-w 2 -b 5 -s 1

Arguments:
-w 2 -b 5 -s 2

Arguments:
-w 2 -b 5 -s 2



Example 4 - Edges From Color Image

Original
(cartoon-sailboat-on-white-background)

Arguments:
(defaults)



Example 5 - Edges From Color Image With Transparency

Original
(clipart-sailboat)

Arguments:
(defaults)



What the script does is as follows:

  • Applies -blur to the image
  • Applies -morphology edge to extract the edges
  • Applies -evaluate multiply to brighten the edges

This is equivalent to the following IM commands

  • filt=`convert xc: -format "%[fx:$smooth/2]" info:`
  • convert $infile -alpha off -blur 0x$filt \
    -morphology edge diamond:$width -evaluate multiply $bri \
    $outfile