Re: [Geoserver-devel] Image pyramid improvements and tutorial

[Stephen V. M. <sv...@cl...>]

Hmm, the embarassment of naïve configuration... .  :D  Let me do some
additional testing on my end.  I assume then that you got the image pyramid
plugin to work without a special version of GeoServer?

Thanks,
Steve
 

 



-----Original Message-----
From: Andrea Aime [mailto:aa...@op...] 
Sent: Monday, March 29, 2010 2:25 PM
To: sv...@cl...
Cc: 'Simone Giannecchini'; geo...@li...
Subject: Re: [Geoserver-devel] Image pyramid improvements and tutorial


Stephen V. Mather ha scritto:
> Hi Simone,
> 	The correct CRS is EPSG:3728, 
> http://spatialreference.org/ref/epsg/3728/, although EPSG:102722 is 
> pretty close.
> 	The size of the tiff is, well, either cheapness or laziness.  The 
> current format, naming convention and size is what has been used by 
> our engineers in CAD for 8 years, and is referenced by all their CAD 
> drawings, and I'm trying to not have two copies of a 160GB dataset.  
> That said, if there's a strong performance gain to be had by retiling 
> to a smaller size, I can squeeze more space out of our RAID.

Hi Stephen,
tried another time, and I could also build the pyramid correctly, though
first I wiped out all the shapefiles and property files you did attach so
that the pyramd plugin could perform its job.

I can see the data just fine after that, though the rendering is quite slow.
The TIFFs are not really very well setup, they do have no inner tiling, yet,
I'm a bit surprised about the slowness. Looked into it and the reason is
that a reprojection is happening, this is due to the native definition
inside the GeoTiff not matching the official EPSG one.

gdalinfo reports:

PROJCS["NAD_1983_StatePlane_Ohio_North_FIPS_3401_Feet",
     GEOGCS["NAD83",
         DATUM["North_American_Datum_1983",
             SPHEROID["GRS 1980",6378137,298.2572221010002,
                 AUTHORITY["EPSG","7019"]],
             AUTHORITY["EPSG","6269"]],
         PRIMEM["Greenwich",0],
         UNIT["degree",0.0174532925199433],
         AUTHORITY["EPSG","4269"]],
     PROJECTION["Lambert_Conformal_Conic_2SP"],
     PARAMETER["standard_parallel_1",40.43333333333333],
     PARAMETER["standard_parallel_2",41.7],
     PARAMETER["latitude_of_origin",39.66666666666666],
     PARAMETER["central_meridian",-82.5],
     PARAMETER["false_easting",1968500],
     PARAMETER["false_northing",0],
     UNIT["US survey foot",0.3048006096012192,
         AUTHORITY["EPSG","9003"]]]

whilst the EPSG database contains:

PROJCS["NAD83(NSRS2007) / Ohio North (ftUS)",
   GEOGCS["NAD83(NSRS2007)",
     DATUM["NAD83 (National Spatial Reference System 2007)",
       SPHEROID["GRS 1980", 6378137.0, 298.257222101, 
AUTHORITY["EPSG","7019"]],
       TOWGS84[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
       AUTHORITY["EPSG","6759"]],
     PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]],
     UNIT["degree", 0.017453292519943295],
     AXIS["Geodetic longitude", EAST],
     AXIS["Geodetic latitude", NORTH],
     AUTHORITY["EPSG","4759"]],
   PROJECTION["Lambert Conic Conformal (2SP)", AUTHORITY["EPSG","9802"]],
   PARAMETER["central_meridian", -82.5],
   PARAMETER["latitude_of_origin", 39.666666666666664],
   PARAMETER["standard_parallel_1", 41.7],
   PARAMETER["false_easting", 1968500.0],
   PARAMETER["false_northing", 0.0],
   PARAMETER["scale_factor", 1.0],
   PARAMETER["standard_parallel_2", 40.43333333333333],
   UNIT["foot_survey_us", 0.30480060960121924],
   AXIS["Easting", EAST],
   AXIS["Northing", NORTH],
   AUTHORITY["EPSG","3728"]]

As you can see there are quite a bit of parameters that are not equal. To
get decent performance you'd need to reproject the tiles to an 
officially supported EPSG code, or create a new one in 
$GEOSERVER_DATA_DIR/user_projections/epsg.properties that matches 1-1 the
WKT of your data

Cheers
Andrea


-- 
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.