Load raster from PostGIS

In [1]:

    

from figutils import query


    

In [1]:

    

from matplotlib import pyplot
%matplotlib inline


    

In [2]:

    

from database.models import Site


    

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Hofgarten = Site.objects.get(name = 'Hofgarten')


    

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Hofgarten.geometry.ewkt


    

    
Out[4]:





'SRID=31254;POINT (80535.11160000041 237665.08)'

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query_sql = u"""SELECT ST_AsGDALRaster(ST_AsRaster((ST_Intersection(raster, ST_Buffer(ST_GeomFromEWKT('{0}'), 100))).geom, raster), 'PNG') 
                FROM public.rast_landcover_merged_publication 
                WHERE ST_Intersects(raster, ST_AsRaster(ST_Buffer(ST_GeomFromEWKT('{0}'), 100), raster));""".format(Hofgarten.geometry.ewkt)


    

In [7]:

    

query_sql = u"""SELECT ST_AsGDALRaster(ST_AsRaster(ST_Buffer(ST_GeomFromEWKT('{0}'), 10), 200, 200), 'PNG')""".format(Hofgarten.geometry.ewkt)


    

In [8]:

    

query_sql


    

    
Out[8]:





"SELECT ST_AsGDALRaster(ST_AsRaster(ST_Buffer(ST_GeomFromEWKT('SRID=31254;POINT (80535.11160000041 237665.08)'), 10), 200, 200), 'PNG')"

In [9]:

    

raster = query.get_raster(query_sql)


    

In [10]:

    

pyplot.imshow(raster, cmap='gray')


    

    
Out[10]:





<matplotlib.image.AxesImage at 0x7f92700e9828>