GIMP unsharp mask plug-in

Update, July 2002: Please note that this page is extremely out of date. The unsharp mask plugin has been included in the GIMP distribution since GIMP version 1.2 (1999). The source code on this page has not kept up with changes made to the version included with the GIMP.

Current version: 0.11
Changelog
Updated January 27, 1999
Download source code.
Download binary for Linux on Intel with glibc 2.1. I compiled this on a Red Hat 6.0 system -- this may or may not work with Red Hat 5.x or other distributions based on glibc 2.0.

Status

This plug-in has been included in the GIMP distribution since version 1.2. The version in the distribution is slightly different (in terms of interface) than the one on this web page.

What is this thing?

An unsharp mask sharpens an image by using a blurred version of the image. The results are generally much more pleasing than a standard sharpen filter, since the unsharp mask doesn't enhance noise as much as a standard sharpen filter. This plug-in is released under the GNU Public License.

Installation

The easiest way to install the plug-in (for linux-intel-glibc) is to download the binary and copy it to your ~/.gimp/plug-ins/ directory, as follows: 
   gunzip unsharp-linux-i386-glibc21.gz
   chmod 755 unsharp-linux-i386-glibc
   mv unsharp-linux-i386-glibc ~/.gimp/plug-ins/unsharp

The other way of installing the plug-in is to compile it yourself. This what everybody using the GIMP on setups other than linux-intel-glibc will have to do, at least for now.
First download the source package. Then type the following, starting in the directory you downloaded the package to: 
   mkdir unsharp
   cd unsharp
   gunzip -c ../unsharp.tar.gz | tar xv
   make
   cp unsharp ~/.gimp/plug-ins/

If you want to install the plug-in so that it is available for all users, you should copy the binary to the global plug-in directory, which is usually /usr/lib/gimp/1.0/plug-ins.

The Unsharp Mask in action:

Here is what the dialog looks like:


This is an example of how the Unsharp Mask can change your life:

Before After
The unsharp mask was applied with radius=6.0, amount=0.5, threshold=0.0.

Known bugs:

To Do (in no particular order):

Useful links: