GIMP Plugin Registry

This plug-in changes colors in an image based on the HSV difference between two colors. This is particularly useful for applying color themes to existing images.
It avoids burning out high saturation and value at the expense of compression them somewhat when the difference goes towards higher saturation and value.
Current bugs/missing features include:
Undo does not work.
It can't be used on indexed images, even though it would frequently have enough colors.  read more »

This plug-in enables you to use the vast number of existing filters made for Photoshop's Filter Factory as well as create new effects without having to go through the process of learning how to write plug-ins for The Gimp first.
Originally written by Jens Restemeier for Gimp 1.x back in 1997, this plug-in has now been updated for use with Gimp 2.x.
Project homepage is at http://gimpuserfilter.sf.net/
You can find lots of free FF filters that can be imported into User Filter at http://www.photoshop-filters.com/  read more »