Hi all,

I am performing segmentation on many Landsat8 scenes stored in PostgreSQL / 
PostGIS. I have a very sub-optimal work-flow (all is done in Python script 
on server side):

   - export tiled raster from PostGIS to .tiff image
   - perform 4 steps of LSMS 
   
<http://otbcb.readthedocs.io/en/latest/Applications/app_LSMSSegmentation.html> 
   segmentation using python API resulting in .shp with segments
   - import this with shp2pgsql back to table in PostGIS.

Although this is working it has several drawbacks


   - I have found that first step of LSMS 
   
<http://otbcb.readthedocs.io/en/latest/Applications/app_MeanShiftSmoothing.html>
 
   is not linear regarding elapsed time and amount of data (see attached 
   image) ... I have found not possible to process with this step whole 
   Landsat8 scene, so I am doing whole before-mentioned pipeline in cycle 
   processing 5 rows (1 consists from tiles of the size 128 x 128 px) loosing 
   advantage of artifacts free result.


<https://lh3.googleusercontent.com/-OZSbkwJOu38/V5mtarcKdfI/AAAAAAAAEZE/e5m8AY74Y0gXs9cfmsOmjLSbXsfDReROQCLcB/s1600/rows_vs_time.jpg>

   - I believe it can be much faster.


Because of that I am trying to find the way, how to pass tiled image from 
PostgreSQL directly to OTB... I have found 
http://wiki.orfeo-toolbox.org/index.php/OTB-PostGIS_Interface but it seems 
to be focused opposite way: expose PostGIS functionality to OTB. I would 
like to expose OTB functionality (actually only LSMS 4 steps) directly to 
PostGIS.


Do you know such existing API?


If there is no such API, I would like to contribute to that. I have 
experience creating API exposing C++ classes / functions to PostgreSQL like 
described in 35.9.13. Using C++ for Extensibility. 
<https://www.postgresql.org/docs/9.4/static/xfunc-c.html>


Best regards, Jiří.

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