[Qgis-developer] Handling of fuzzy boundaries

[Annina Hirschi Wyss]

Hello,

I'm preparing my master's thesis on the subject of handling fuzzy objects using the fuzzy logic, with the focus on geometries (not on the thematic level).
I wanted to know, if there has already been a discussion about implementing this in QGIS or in a plugin.

Showing the uncertainty of boundaries is needed in some cases of spatial planning, when the "crisp" geometries are not yet defined.

A possible use case could also be to draw a polygon with certain attributes, then the border of the polygon "copied" to one or more oriented polyline layers with special attributes (e. g. the distance of the uncertainty, to which the fuzzy-function is applied). These polylines are linked by a foreign key to the polygon-feature. This would certainly require the use of a database, namely Postgre/PostGIS.
A polyline layer (linked to the polygon) can also be "crisp" e.g. if the border is a street or a river. So it should be possible to combine crisp and fuzzy segments for the same polygon.
Visualising this could result in a polygon with a sort of "thick pen-trace"  (the thickness corresponding to the distance-attribute of the polyline) boundary, showing the uncertain band. The thickness corresponds to the distance-attribute of the polyline.

Another possible visualisation (sort of fuzzy buffers) is presented in the following paper: http://www.geo3.nl/12%20fuzzy%20set%20theory.pdf (fig. 1b).

If there are developers interested in this, I would be glad to know, as my own programming skills are rather basic.

Thanks in advance
Annina