NAME

selective_sharpen - Sharpen edges in controlled fashion

SYNOPSIS

<Image>/Filters/Enhance/Selective Sharpen...

DESCRIPTION

Taken from an IRC log:

  02:00 <@         tigert> selective sharpening
  02:00 <@         tigert> UnNamed: 1) take the original photo, duplicate the
                           layer
  02:01 <@         tigert> UnNamed: 2) convert the copy to grayscale
  02:01 <@         tigert> 3) run edge detect to the gray layer
  02:01 <@         tigert> 4) blur it slightly
  02:01 <@         tigert> 5) boost contrast (I can give you a specific curve or
                           such)
  02:01 <        sjburges> tigert: on 3, what edge detect?
  02:01 <@         tigert> sjburges: default works
  02:01 <@         tigert> sjburges: size: 3 or 2 (default)
  02:02 <@         tigert> sjburges: then make the boosted, gray edge-detection
                           into a selection mask
  02:02 <@         tigert> sjburges: then use unsharp mask to that selection
                           (scratch the gray layer)
  02:03 <@         tigert> sjburges: sjburges now, one could do two versions
  02:03 <@         tigert> sjburges: so one version could just be "Select edges"
  02:04 <@         tigert> sjburges: another could ask for unsharp mask
                           parameters as well and sharpen
  02:04 <@         tigert> sjburges: the idea for the script is to sharpen it
                           without sharpening the noise on flat areas
  02:04 <        sjburges> tigert: could you fire me an email, and I can try to
                           get to it tonight/tomorrow?  It sounds simple enough.
                           I need to head to a party for work shortly here
  02:04 <@         tigert> sjburges: ok

PARAMETERS

 [ PF_SPINNER, "sharpen_radius", "Radius of unsharp", 5.0, [0.1,120,0.1]],
 [ PF_SPINNER, "sharpen_amt", "Amount to unsharp", 1.0, [0.0,4.0,0.1]],
 [ PF_SPINNER, "threshold", "What delta to decide to sharp on", 20, [0,255,1]],

IMAGE TYPES

RGB*

AUTHOR

Seth Burgess <sjburges@gimp.org>

DATE

2004/14/04

LICENSE

Copyright 2004, Seth Burgess.

This filter may be distributed under the same terms as Gimp-Perl.