[OSM-legal-talk] Infringements - examples, analysis and request for removal

"Petr Morávek [Xificurk]" xificurk at gmail.com
Sat Mar 31 14:52:38 BST 2012

Darko Sokolić wrote:
> I this analysis I've covered 7329 nodes.
> I was looking for situations where any of these nodes is deleted by
> another user, and then new node is created on similar location in the
> same changeset. Then I grouped results by positional error, that is
> distance between new and old node.
> This is what I found (grouped by author of replacement nodes):
> for positional error of up to cca 11 m in latitude and 7,8 m in
> longitude (that is 4 decimal digits in LAT/LON in OSM database):
>  SilverSpace |  4565 nodes (62% of all analysed nodes)
>  Janjko      |  1363 nodes (19%)
> for positional error of up to cca 1,1 m in latitude to 0,78 m in longitude:
>  SilverSpace |  2909 (40%)
>  Janjko      |   758 (10%)
> For first group we might argue that cca 10 meters is large distance and
> that any usual remapping would fit in (but visual comparison of rendered
> data reveals similarities).
> In the second group, where positional error is up to cca 1 m - it is
> very hard to defend this as not infringement.
> I started to analyse not only maximum deviations, but averages, and
> standard deviations, and also I looked into minimal positional errors.
> And the I found that significant number of replacement nodes are placed
> on the _very_same_position_ of original node (again - in the same
> changeset):
>  SilverSpace |  2235 (30%!)
>  Janjko      |   260 (3,5%)
> We are talking here about precision of lat/lon in 7 decimal places. This
> is precision of about 11 mm in latitude and 7,8 mm in longitude. In 34%
> of sampled data. This is not a coincidence. This is intentional
> infringement.


and what was the source of that data in the first place?
It's not surprising that you get similar results if two people are using
the same datasource for tracing.
The precision is pretty high, but it still does not imply that they
copied your data. E.g. if you algorithmically trace some bitmap
datasource with a tool like JOSM plugin Tracer, then you SHOULD get very
similar results as anyone else going through the same process.
The overall precision of similarity depends on what objects are you
tracing as well.

You did not state your original datasource, neither any specific
examples, only that you have found certain degree of similarity in your
data and replacement data - well, what's surprising about that? You've
both mapped the same objects, there would be something terribly wrong if
the results weren't similar :-)

Can you give us more information about the original data and some
examples of replacement changesets?

Best regards,
Petr Morávek aka Xificurk
-------------- next part --------------
A non-text attachment was scrubbed...
Name: xificurk.vcf
Type: text/x-vcard
Size: 211 bytes
Desc: not available
URL: <http://lists.openstreetmap.org/pipermail/legal-talk/attachments/20120331/69bbe444/attachment.vcf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 262 bytes
Desc: OpenPGP digital signature
URL: <http://lists.openstreetmap.org/pipermail/legal-talk/attachments/20120331/69bbe444/attachment.pgp>

More information about the legal-talk mailing list