Re: [OSM-dev] Detect and remove sharp angle/spiky configurations on buildings

2018-10-18 Thread Pierre Béland
 oups, Resending previous incomplete message

Sandor, 
 you are looking only at spikes. My algorithm presented in recent threads on 
the talk list about Building Geometries detection will also detect regular 
geometries that have any irregular edge ( a difference of more then 2 degrees 
).  It cannot distinguish valid irregular geometries, but they are in general a 
small numbers, and most flagged buildings correspond to imprecise building 
traces.

regular polygons-   90, 90, 90, 90
-   90, 270, 90, 90, 90, 90
-  120 * 6 (hexagon)-  135 * 8 (octagon)

refhttps://lists.openstreetmap.org/pipermail/talk/2018-August/081274.htmlhttps://lists.openstreetmap.org/pipermail/talk/2018-September/081392.html
 
 
Pierre 
 

  

Pierre 
 

Le jeudi 18 octobre 2018 09 h 15 min 53 s HAE, SandorS 
 a écrit :  
 
 
Some days ago there was a question on an OSM forum whether such algorithm 
exists and used by some of the OSM users. Honestly I even did not know that 
such an issue exists and probably I am not alone. The reason to that is either 
that the spiky configurations are hardly visible in maps or that robust users 
handle them as a special case when process tiny outgrowths in their data 
generalisation programs. A closer look at the issue has shown that the issue is 
real and rather general. Spiky configurations exist on most of the area 
borders, roads, roundabouts and so on, there is a huge number of them and 
almost all are errors. To provide strong arguments about the former statement I 
have made an algorithm, a simplified version of the tiny outgrowths detection 
and removal, and applied the corresponding program to the OSM UK buildings. The 
algorithm on a certain abstraction level, its use and the processing results 
are described in details in an article here 
https://drive.google.com/open?id=1MaLdnSnc454xKjn3eL95vDQKeoIW8zGU . There are 
around 120K spiky buildings in OSM and out of these 2834 in the UK. In 
addition, the paper presents many examples how the spiky buildings look before 
and after the correction. Also, the paper contains links to the output data of 
the demo/test processing and how these could be used for visual analyses. So, 
if interested, enjoy the paper.

Regards, Sandor.

  

  

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Re: [OSM-dev] Detect and remove sharp angle/spiky configurations on buildings

2018-10-18 Thread Pierre Béland
Sandor,  you are looking only at spikes. My algorithm presented in recent 
threads  about Building Geometries detection will also detect either 
rectangular, ortogonal etc. geometries that have any irregular angle ( a 
difference of more then 2 degrees ).Regular geometry 
- 90, 90, 90, 90

refhttps://lists.openstreetmap.org/pipermail/talk/2018-August/081274.htmlhttps://lists.openstreetmap.org/pipermail/talk/2018-September/081392.html
 
Pierre 
 

Le jeudi 18 octobre 2018 09 h 15 min 53 s HAE, SandorS 
 a écrit :  
 
 
Some days ago there was a question on an OSM forum whether such algorithm 
exists and used by some of the OSM users. Honestly I even did not know that 
such an issue exists and probably I am not alone. The reason to that is either 
that the spiky configurations are hardly visible in maps or that robust users 
handle them as a special case when process tiny outgrowths in their data 
generalisation programs. A closer look at the issue has shown that the issue is 
real and rather general. Spiky configurations exist on most of the area 
borders, roads, roundabouts and so on, there is a huge number of them and 
almost all are errors. To provide strong arguments about the former statement I 
have made an algorithm, a simplified version of the tiny outgrowths detection 
and removal, and applied the corresponding program to the OSM UK buildings. The 
algorithm on a certain abstraction level, its use and the processing results 
are described in details in an article here 
https://drive.google.com/open?id=1MaLdnSnc454xKjn3eL95vDQKeoIW8zGU . There are 
around 120K spiky buildings in OSM and out of these 2834 in the UK. In 
addition, the paper presents many examples how the spiky buildings look before 
and after the correction. Also, the paper contains links to the output data of 
the demo/test processing and how these could be used for visual analyses. So, 
if interested, enjoy the paper.

Regards, Sandor.

  

  

Sent from Mail for Windows 10

  
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[OSM-dev] Detect and remove sharp angle/spiky configurations on buildings

2018-10-18 Thread SandorS
Some days ago there was a question on an OSM forum whether such algorithm 
exists and used by some of the OSM users. Honestly I even did not know that 
such an issue exists and probably I am not alone. The reason to that is either 
that the spiky configurations are hardly visible in maps or that robust users 
handle them as a special case when process tiny outgrowths in their data 
generalisation programs. A closer look at the issue has shown that the issue is 
real and rather general. Spiky configurations exist on most of the area 
borders, roads, roundabouts and so on, there is a huge number of them and 
almost all are errors. To provide strong arguments about the former statement I 
have made an algorithm, a simplified version of the tiny outgrowths detection 
and removal, and applied the corresponding program to the OSM UK buildings. The 
algorithm on a certain abstraction level, its use and the processing results 
are described in details in an article here 
https://drive.google.com/open?id=1MaLdnSnc454xKjn3eL95vDQKeoIW8zGU . There are 
around 120K spiky buildings in OSM and out of these 2834 in the UK. In 
addition, the paper presents many examples how the spiky buildings look before 
and after the correction. Also, the paper contains links to the output data of 
the demo/test processing and how these could be used for visual analyses. So, 
if interested, enjoy the paper.
Regards, Sandor.


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