[postgis-devel] [PostGIS] #340: [wktraster] Implement ST_AsJPEG function for raster

[PostGIS]

#340: [wktraster] Implement ST_AsJPEG function for raster
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  Reporter:  mloskot    |       Owner:  mloskot        
      Type:  task       |      Status:  assigned       
  Priority:  medium     |   Milestone:  WKTRaster 0.1.6
 Component:  wktraster  |     Version:  trunk          
Resolution:             |    Keywords:                 
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Old description:

> This tasks belongs to the Objective 0.1.6f specified in the
> [wiki:WKTRaster WKT Raster]
> [wiki:WKTRaster/PlanningAndFunding roadmap]
>
>  ''to be discussed here''

New description:

 This tasks belongs to the Objective 0.1.6f specified in the
 [wiki:WKTRaster WKT Raster]
 [wiki:WKTRaster/PlanningAndFunding roadmap]

 As stated at the end of the comment 5 of the "Specification Comments
 following the Code Sprint" section of the working specifications, this
 function should be a PL/pgSQL wrapper around a more general
 ST_AsImage(format, params) function using GDAL to convert any raster to an
 image.

 The function should return a bytea.

 This function is particularly sensible to the number of band present in
 the raster as it normally needs 3 band (r,g,b).

 It is also very sensible to the pixel type of the raster since JPEG
 supports only values in the 0-255 range.

 See the working specifications for more details/questions.

 Priority should be given to these variants:

 ST_AsJPEG(raster, integer)
 ST_AsJPEG(raster, integer, integer, integer, integer)
 ST_AsJPEG(raster, integer, "GRAYSCALE", integer, min, max, text)

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/340#comment:3>
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