Hi Julien,
Your description matches the functionality of the GyrusFinder plugin,
except that it works in 3-D (and it has not really been maintained
over the past 10 years). The folks at MCW asked for a 2-D version
long ago, but unfortunately that has not come to be.
Enclosing regions in 3-D is a bit more challenging, but you might
consider giving it a try. It is an old plugin meant for unscaled
short datasets. But if more people found it useful, that would be
encouragement to enhance it...
- rick
