[Imports] Import/Bulk Edit classifications

[Drew Moffitt]

I am not speaking of a complete 100% unsupervised data gather or being 100%
digitized manually.  Rather, a process by which imagery is classified into
water/terrestrial and then a manual review of that water to a known and
recent (might I add USDA) imagery source.

There are many ways to do a supervised/unsupervised classification of
Landsat and convert that to a vector: ERSAS Imagine or ArcGIS are my two
flavors.  It's a fairly straight forward operation with water extraction
given its appetite for IR bands
(http://web.pdx.edu/~emch/ip1/bandcombinations.html).  Small Bezier routines
applied afterwards enhance the boundary appearance. 

So, I ask again, do you still think this is an import?




-----Original Message-----
From: Paul Norman [mailto:penorman at mac.com] 
Sent: Friday, October 19, 2012 10:55 PM
To: 'Drew Moffitt'
Cc: imports at openstreetmap.org
Subject: RE: [Imports] Import/Bulk Edit classifications

What do you mean by extract? Landsat is raster data, there aren't any
vectors to extract.

If you mean digitize, it would depend on how. If you were digitizing by
tracing, that wouldn't be regarded as an import. Tracing from imagery
without any local knowledge or knowing the situation on the ground can have
issues sometimes, but they're not the issues of imports.

On the other hand, someone proposed an import of buildings that were
automatically generated by analysis of multispectral imagery. I think that'd
pretty clearly be an import.

Of course, there's always the middle ground. You could have tools similar to
photoshop's smart selection tools that do the tracing for you. Fortunately
for figuring out how to classify these things, most of the uses clearly fall
on one end or the other.

As an aside, automatic digitization of features works best on irregular
natural features where people are not expecting straight lines. Applied to
man-made features with straight lines and right angles the results are not
ideal.

> From: Drew Moffitt [mailto:dmm at ftn-assoc.com]
> Sent: Friday, October 19, 2012 8:57 AM
> To: 'Paul Norman'
> Subject: RE: [Imports] Import/Bulk Edit classifications
> 
> What if I take Landsat Imagery, extract the water data areas and bring 
> those in.  Is that an import?
> 
> -----Original Message-----
> From: Paul Norman [mailto:penorman at mac.com]
> Sent: Friday, October 19, 2012 12:32 AM
> To: imports at openstreetmap.org
> Subject: [Imports] Import/Bulk Edit classifications
> 
> I had originally posted some of this to a wiki talk page, but
> 
> On interesting (for those who careabout this) question that's come up 
> is how to classify the range of imports.
> 
> On the one end, we have the typical large imports ranging from TIGER 
> and Corine to CanVec and European cadastral data
> 
> On the other end, we have cases like the cyclestreets snapshot-server 
> and
> potlatch2 setup where properties and vectors can be brought through 
> from a background layer.
> 
> Some other interesting cases (some hypothetical, or with changed 
> names)
> 
> - The Czech community used a bot to fix problems with borders in the 
> area.
> The bot also used an external data source in the process. Is this an 
> import?
> Mechanical edit? Bot?
> 
> - I surveyed a new interchange but didn't get a usable GPS trace for 
> all of the overpasses. I had a data source that agreed with my survey 
> and was more complete, so I used it instead. I spent a significant 
> amount of time making sure all the relations and tagging not in the source
(e.g.
> bike access) was carried over. Is this an import? In this case it was 
> CanVec so I could handle it either as an import or not, but I have 
> other sources for other areas that are legally compatible used that 
> haven't gone through any import consultation.
> 
> I'm sure people are using data sources in ways I haven't thought of 
> yet, and I'd be interested in hearing about those too.
> 
> This is fairly open-ended because I not only don't know the answers, I 
> don't know the questions.
> 
> 
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