[postgis-devel] [PostGIS] #1536: [raster] There should be an option for setting the nodata value in certain variants of ST_Intersection(raster, raster)

[PostGIS]

#1536: [raster] There should be an option for setting the nodata value in certain
variants of ST_Intersection(raster, raster)
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 Reporter:  pracine  |       Owner:  pracine      
     Type:  defect   |      Status:  assigned     
 Priority:  low      |   Milestone:  PostGIS 2.0.0
Component:  raster   |     Version:  trunk        
 Keywords:           |  
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Changes (by pracine):

  * status:  new => assigned


Comment:

 So here are the list of changes I'm planning:

 -Removal of the extenttype parameter. ST_Intersection should always return
 the geometrical intersection of both raster. If you want something else
 use ST_MapAlgebra() or the future ST_SymDifference() or ST_Difference().

 -A new set of ST_Intersection() variant accepting an array of nodata
 values. The number of values in the array should match the number of band
 requested (FIRST and SECOND: 1, BOTH: 2). I'm worry about the third case:
 OTHER... What should we do in this case? What is the need for this option
 anyway?

 -When one of the input raster corresponding to a requested band do not
 have a nodata value defined but the other one does AND no nodata value
 array is provided, we will set the nodata value of the one missing it to
 ST_MinPossibleValue() with a warning similar to the one planned in
 ST_Clip() (see #1581): "The FIRST (or SECOND) band did not have a nodata
 value defined and no nodata value were provided. Setting the FIRST (or
 SECOND) band nodata value to XXX. Use a variant accepting a nodata array
 to define it yourself." Very long notice...

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1536#comment:24>
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