[postgis-users] ST_Reclass - oposit direction in reclass

[Stanislav Vanecek]

Hi
 I am using the ST_Reclass to create 3-band TIFF (for graphical
presentation) from 1 band grid 32BF (using algorithm described in 32BF
http://postgis.refractions.net/documentation/manual-svn/RT_ST_Reclass.ht
ml)
The problem is, then for the mapping both intervals in (reclassexpr
text) must be increasing  - values from small to high is mapped to
colors from "small  to high" = (black to white for example) - and I like
to have them in opposite order.
I am working with the big rasters (2000 x 2000 cells). In this case the
ST_Reclass is already not very fast - and when I try to use map algebra
it was very, very slow.
Did someone have idea how to speed up?
Thank you
Standa