[ka-Map-users] Improving ka-map speed with non-cached WMS?

Stephen Woodbridge woodbri at swoodbridge.com
Mon Dec 14 18:01:58 EST 2009

There may be other or even better ways of dealing with this, but my 
strategy has been convert all the imagery to uncompressed GTIFF data 
using an internal tiled format which is the most efficient for mapserver 
to access. And then to run gdaladdo on top of those. Really large files 
will probably need to be tiled into smaller tiles and then built a 
tileindex to stitch it all back together again. This will give you good 
mapserver performance at the cost of disk space. If you data is getting 
update and you need to remove old imagery and replace it, then use some 
kind of directory structure to help manage that, for example if you have 
a file xxx.sid create a directory xxx_sid and put the tiles in there. 
then if you need to replace xxx.sid in the future it is easy to remove 
the old tiles and create new ones.


Bistrais, Bob wrote:
> We have our imagery data for the WMS services in three different
> formats- JP2, SID, and GTIFF.  I've been doing most of my testing with
> the jp2, since that's statewide orthoimagery.
> The application is presenting the WMS service in PNG24.
> A gdalinfo for one of the images gives the following:
> Driver: JP2ECW/ERMapper JPEG2000
> Files: C:\naip_07\tiles\augusta_nw.jp2
> Size is 5655, 7594
> Coordinate System is:
> LOCAL_CS["unnamed",
>     UNIT["unknown",1]]
> Origin = (429916.000000000000000,4914197.000000000000000)
> Pixel Size = (1.000000000000000,-1.000000000000000)
> Corner Coordinates:
> Upper Left  (  429916.000, 4914197.000)
> Lower Left  (  429916.000, 4906603.000)
> Upper Right (  435571.000, 4914197.000)
> Lower Right (  435571.000, 4906603.000)
> Center      (  432743.500, 4910400.000)
> Band 1 Block=5655x1 Type=Byte, ColorInterp=Red
>   Overviews: arbitrary
> Band 2 Block=5655x1 Type=Byte, ColorInterp=Green
>   Overviews: arbitrary
> Band 3 Block=5655x1 Type=Byte, ColorInterp=Blue
>   Overviews: arbitrary
> As for the mapfile layer- do you mean the mapfile which consumes the WMS
> (part of the ka-map app), or the file which creates the WMS service?  If
> you mean the file which consumes the WMS, this is it:
> #NAIP Orthoimagery
>   GROUP "NAIP2007_Imagery"
>   NAME "naip2007"
>   TYPE raster
>   CONNECTION "http://myserver/wms/mapserv.exe?map=c:/wms/orthos.map&"
>     "wms_server_version" "1.1.1"
>     "wms_format" "image/png"
>     "wms_title" "NAIP"
>     "wms_abstract" "NAIP 2007 imagery"
>     "wms_srs" "EPSG:26919"
>     "wms_onlineresource" "MaineOrthos-NAIP"
>     "wms_name" "naip2007,naip10moverview,naip100moverview"
>     "queryable" "false"
>     "tile_source" "nocache"
>     "imageformat" "PNG24"
>   END
> -----Original Message-----
> From: Stephen Woodbridge [mailto:woodbri at swoodbridge.com] 
> Sent: Thursday, December 10, 2009 3:14 PM
> To: Bistrais, Bob
> Cc: ka-map-users at lists.maptools.org
> Subject: Re: [ka-Map-users] Improving ka-map speed with non-cached WMS?
> Bistrais, Bob wrote:
>> I have a ka-map application which consumes WMS services, consisting of
>> various imagery layers.  We don't want to precache tiles for the WMS.
>> We also have precached tiles for vector data in the application.
>> I don't know if it matters, but the web server uses IIS, not Apache.
>> Other viewers, such as ArcGIS and Quantum GIS, can consume the same 
>> WMS services and have much faster draw times than our Ka-Map
> application.
>> We would like to see improved draw times for the WMS imagery, again, 
>> without precaching it.  Can anyone make recommendations or point me to
>> a resource discussing this?
> Bob,
> Probably need more information like:
> What your mapfile LAYER looks like?
> What format is the raster data in?
> What does gdalinfo /path/to/a/raster.file look like?
> and this is really a question about how to increase performance of
> raster data from mapserver and might get a better response from that
> list.
> I think there is a page(s) in mapserver docs on how to do this:
> http://www.google.com/#hl=en&source=hp&q=mapserver+raster+performance
> -Steve

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