[postgis-devel] [PostGIS] #606: [raster] ST_Value should return NULL for nodata values

[PostGIS]

#606: [raster] ST_Value should return NULL for nodata values
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 Reporter:  pracine         |       Owner:  pracine      
     Type:  enhancement     |      Status:  assigned     
 Priority:  critical        |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
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Comment(by pracine):

 There should be a boolean option to disable this behavior and return the
 true value of a nodata value pixel if required.

 ST_Value(rast, x, y, FALSE)

 In this case FALSE means "ignore the nodata value flag" or "do not take
 nodata value into account and treat any nodata value like withdata
 values".

 By default the boolean option is TRUE and the function returns NULL (if
 the value is nodata).

 This boolean option have the same meaning as the one in st_intersects and
 should be generalize to every fucntion when we want it to ignore nodata
 values.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/606#comment:3>
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