[postgis-devel] [PostGIS] #1293: [raster] ST_Resize to resize raster tiles

[PostGIS]

#1293: [raster] ST_Resize to resize raster tiles
-------------------------+--------------------------------------------------
 Reporter:  robe         |       Owner:  pracine              
     Type:  enhancement  |      Status:  new                  
 Priority:  medium       |   Milestone:  PostGIS Raster Future
Component:  raster       |     Version:  trunk                
 Keywords:               |  
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Description changed by pracine:

Old description:

> Bborie,
>
> I'm ticketing what we discussed.  As mentioned, it would be nice to have
> a resize function that provides the similar functionality to
> gdal_translate that can take a percentage reduction or max pixel
> dimensions.
>
> e.g.
>
> what gdal_translate:
>

> {{{
> gdal_translate -of png -outsize 25% 25% original.png final.png
> gdal_translate -of png -outsize 500 500 original.png final.png
>
> }
>
> Currently have to use ST_Resample for this which requires a lot more
> arguments, not to mention it doesn't seem to work for rasters with no
> srid information.
>
> I'm envisioning the signature would look something like
>

> {{{
> ST_Resize(rast raster, width text, height text)
> }}}
>

> where width can be a numeric like '500'  or can be a percentage like
> '50%' which is why I made it text.
>
> This will make postgis raster useful for both GIS folks and non-GIS folks
> as having an easy function to resize a raster will speed up all kinds of
> analysis.  Like I mentioned, my selfish need is that most of my raster
> projects do not involve objects that fit in a nice spatial reference
> landscape but the analysis functions we've got so far I'm finding very
> useful for those (e.g. image recognition, and just plotting and
> vectorizing non-GIS like things like anatomic parts, or construction
> objects)

New description:

 Bborie,

 I'm ticketing what we discussed.  As mentioned, it would be nice to have a
 resize function that provides the similar functionality to gdal_translate
 that can take a percentage reduction or max pixel dimensions.

 e.g.

 what gdal_translate:


 {{{
 gdal_translate -of png -outsize 25% 25% original.png final.png
 gdal_translate -of png -outsize 500 500 original.png final.png

 }}}

 Currently have to use ST_Resample for this which requires a lot more
 arguments, not to mention it doesn't seem to work for rasters with no srid
 information.

 I'm envisioning the signature would look something like


 {{{
 ST_Resize(rast raster, width text, height text)
 }}}


 where width can be a numeric like '500'  or can be a percentage like '50%'
 which is why I made it text.

 This will make postgis raster useful for both GIS folks and non-GIS folks
 as having an easy function to resize a raster will speed up all kinds of
 analysis.  Like I mentioned, my selfish need is that most of my raster
 projects do not involve objects that fit in a nice spatial reference
 landscape but the analysis functions we've got so far I'm finding very
 useful for those (e.g. image recognition, and just plotting and
 vectorizing non-GIS like things like anatomic parts, or construction
 objects)

--

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1293#comment:6>
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