Ahhh, you'll be looking for a while. :)  PostGIS raster does not currently 
interpret raster band data as color information. If it started out as RGB, you 
can input all three bands and manipulate them however you see fit. However, you 
can't output a color jpeg/png if you're starting with a single band of data. 
Additionally, if you import a single band image with associated pallete, you'll 
lose the color information. On the upside, if you have a full color image, you 
can read it in manipulate it, and spit it back out.

Try exporting the single band of interest, then adding a pallete using the 
external program of your choice. That will also let you "stretch" the image to 
your heart's content. I'm 90% sure you can do all your desired postprocessing 
with ImageMagick. :)

Bryce

-----Original Message-----
From: postgis-users-boun...@postgis.refractions.net 
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Stephen 
Crawford
Sent: Wednesday, December 21, 2011 3:51 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] raster output

Thanks for getting back to me.  I want to do something like #3, but I just 
don't understand the work flow.  I have raw data as a one band raster in 
postGIS, and the (seemingly) simple thing i would like to do is output the 
entire table as a  jpg or png with the cells classified by color.  I see 
references to "color tables" and "palettes".  I can't seem to figure out where 
I can define "if cell val < 0.5, color = 0, 0, 255" etc.


_______________________________________________
postgis-users mailing list
postgis-users@postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users

Reply via email to