[postgis-users] How to perform st_PixelAsPolygon(rast, geom) ?

[Hugues François]

Hello,

 

I need to work with a dem raster at the pixel scale but there are few functions to access them. Maybe I forgot something but, if we can have a value crossing a point with raster using st_value, we can't access the pixel geometry directly from a point.

 

The only way I found was first to use St_PixelAsPolygons to access pixel geometry (for relevant tiles) and then intersects resulting geometries with original points but this method costs very much.

 

Anyone have an idea to increase performances ?

 

Hugues.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20130405/884acfe4/attachment.html>