[OSM-talk] The long tail - lowest common denominator

[Lars Aronsson]

Nick Black wrote:

> I'm not sure that I am  following you Lars - do you mean that we could
> use automatic feature detection to detect the edges of water features?

Yes, that's what I was philosophizing about.  But I haven't tried 
it or even planned to try it.  I'm far too lazy for that.

The Landsat images are not perfect, of course, but they do show 
rivers and lakes in some greater detail than the VMap0 data.  
Except where white clouds hide every detail (such as over 
Trondheim), and except where some other dark features appear (such 
as railroads), the dark blue is water and the rest is land.  Just 
filter out the dark blue, and you have a rough estimate of where 
the water is.  Combine this rough estimate with the one given by 
VMap0, and you should be able to arrive at something better.


-- 
  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se