[postgis-devel] [PostGIS] #795: [raster] ST_Intersects raster documentation is confusing
PostGIS
trac at osgeo.org
Wed Jan 19 13:32:41 PST 2011
#795: [raster] ST_Intersects raster documentation is confusing
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Reporter: pracine | Owner: pracine
Type: enhancement | Status: new
Priority: medium | Milestone: PostGIS 2.0.0
Component: postgis raster | Version: trunk
Keywords: |
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The description says: "Returns true if any pixel in a raster band has a
value that is not nodatavalue and that geometry region of the pixel
intersects the geometry. If hasnodata is passed in, then it will use that
to consider if it needs to analyze pixels (true) means analyze pixels, if
the convexhull intersects the geometry. false means just return true if
the convex hull of the raster intersects with the geometry. If hasnodata
is omitted, it reads the value from the meta data of the raster."
The last part of the sentence is false.
Better proposition:
-"Returns true if the geometry intersects with the raster. Nodata values
are taken into account so that if the geometry intersects only with nodata
values, the function returns false. hasnodata may modify this behavior: if
set to false, nodata value are not taken into account and the function
returns true as soon as the geometry intersects with the convex hull of
the raster."
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Ticket URL: <http://trac.osgeo.org/postgis/ticket/795>
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