This procedure looks interesting. It is a kind of edge-preserving blurring.

Links:

• http://www.roborealm.com/help/Bilateral.php
• http://www.cs.ucf.edu/courses/cap6412/spr2003/2003/Bilateral Filter and Applications.pdf
• http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/MANDUCHI1/Bilateral_Filtering.html

It has been implemented in Fiji under Plugins>Process>Bilateral Filter currently (the plugin is in the VIB_.jar)