[postgis-users] Problem to visualize raster data from PostGIS inQGIS

[Hugues François]

Hello,

 

To display raster data, you can try ST_DumpAsPolygons into Arcgis or OpenJump (if it is just a test, you could add a where clause on tile id).

 

WITH a AS (select ST_DumpAsPolygons(rast) AS mydump from deforested_areas –where rid = 1)

 

SELECT (mydump).val, (mydump).geom FROM a

 

This website is a bit outdated, but you can find some useful insights : http://trac.osgeo.org/postgis/wiki/WKTRaster

 

Hug

 

 

De : postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] De la part de Roberto Lazarte Kaqui
Envoyé : mardi 31 mars 2015 15:11
À : postgis-users at lists.osgeo.org
Objet : [postgis-users] Problem to visualize raster data from PostGIS inQGIS

 

I have two multiband raster files and i'm trying to load these data into PostGIS using “raster2pgsql”. 

Here is the syntax that i used:

 

raster2pgsql -c -s 4326 -I -t 100x100 *.tif  public.deforested_rasters | psql -d r342471958

 

It works without error, but i don't know if the command loads correctly both raster files. The database in PostGIS has two columns, one with the spatial index and the other one with raster information. I'm trying to visualize the resultant database in QGIS, but for some reason it doesn't open the raster layer.

I've tried to solve this problem using this idea: https://duncanjg.wordpress.com/2012/11/20/the-basics-of-postgis-raster/ <https://duncanjg.wordpress.com/2012/11/20/the-basics-of-postgis-raster/> , transforming the raster data to geometry data through DB manager using this command:

 

select rid,rast::geometry from deforested_rasters

 

but when visualized in QGIS, only returns a rectangular area without the original characteristics.

Any ideas of how can i confirm that the “raster2pgsql” command loads correctly the raster files? Or a different way to load these data into PostGIS?

The raster files are available in:https://www.dropbox.com/sh/nu8nl6cigv8viz1/AADTrr_w8SCstDHOu6AiGeJta?dl=0 <https://www.dropbox.com/sh/nu8nl6cigv8viz1/AADTrr_w8SCstDHOu6AiGeJta?dl=0> 

 

Thanks,

Roberto

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20150331/b2bd5bb9/attachment.html>