>>>> De : Lester Caine <les...@lsces.co.uk>
>>>> Now that I understand what is going on, I can see where some off the
'extra' lines come from, and the diagonal is probably due to a boundary
detail from changing sheets.
This is more often due to split of landuse ownership. There is no differences
between this lines and the one separating adajacent buildings
>>>> However while the source has two different
shades of block for buildings.
>>>>I don't think they can be used at this
stage to provide useful extra lines.
>>>>The process that is extracting the
vectors should further process the data so that each block IS a single
continuous outline?
>>>>Later comparison will then be easier as long as say
90% of the area matches the previous instance?
No this is not sufficiant I think because some times you have adjacent
buildings that are not a single building. You also have cases when line
separate building parts which have different number of levels or which are
"light buildings" ( without wall by example )
>>>> Of cause simply
importing thousands of these objects without a visual check of every one of
them is something completely different to hand tracing every one of
them.
>>>> I'd prefer that there was some cross check that objects have been
verified.
>>>> And in my book, having to manually select objects to import
would provide that check?
>>>> So I'd block any area select function, so that hundreds of objects can't
>>>> simply be picked and pushed?
Please also notice that this is sometime not easy to distinguish on aerial
imagery if the split line really exist or not.
Cheers
Julien
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