[OSM-talk] protocol for adding buildings using aerial imagery?

[Milo van der Linden]

The first person that automates tracing buildings from yahoo images on
Aruba will be slapped by me!

Besides regulare displacement, the entire imagery is off by 10~100m ,
way to clouded and low res. So please, please, please do not start
some global bot that will place buildings all over..

2010/12/28 Frederik Ramm <frederik at remote.org>:
> Hi,
>
> charlie at cferrero.net wrote:
>>
>> This is a major issue when tracing tower blocks - the taller the building
>> the more the roof appears to be displaced relative to the floor due to the
>> perspective of the plane taking the photos.  I have always tried to map the
>> base because, ultimately, a map is a representation of what's at
>> ground-level.  If you mapped roofs you'd get very tall buildings overlapping
>> the surrounding roads.
>
> Sometimes I map the roof to get a good idea of the shape, then move the
> result to match the base.
>
> It would be interesting to have editor support for estimating the building
> height depending on that displacement, or depending on the extent of the
> shadow - that would have to be calibrated for each imagery and location of
> course but so does the displacement of the whole image, and we're seeing
> people working on the latter...
>
> Bye
> Frederik
>
> --
> Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"
>
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