[postgis-tickets] [PostGIS] #2807: [raster] ST_MapAlgebra injecting a default NODATA value of 0

[PostGIS]

#2807: [raster] ST_MapAlgebra injecting a default NODATA value of 0
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 Reporter:  strk    |       Owner:  dustymugs    
     Type:  defect  |      Status:  new          
 Priority:  medium  |   Milestone:  PostGIS 2.2.0
Component:  raster  |     Version:  trunk        
 Keywords:          |  
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Changes (by dustymugs):

  * milestone:  => PostGIS 2.2.0


Comment:

 After reviewing the code, it looks like the decision to force a NODATA
 value was something decided a long time ago with Pierre and David Zwarg.
 By default, ST_MapAlgebra attempts to get the NODATA value from band
 referred to by the extent parameter. If the band has no NODATA value, it
 gets set to the minimum possible value for the pixel-type.

 I have no problems with the output raster having no NODATA value if the
 input band has no NODATA value. Hopefully Pierre can chime in.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/2807#comment:1>
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