[mapserver-users] Re: Help (tips&tricks) on raster datasetoptimization

[Rahkonen Jukka]

Hi,

The main point is to build overviews for the whole site, isn't it? And then one input will be enough for Mapserver. Tileindex does not understand overviews, and if such are created as an external image, the overview image must be combined with the tileindex layer by putting them into same GROUP and add some scale dependency. It works also well, but your solution is more simple to use. Only disadvantage I can see there is that in my tests a long time ago Mapserver was quite a lot faster if it was using tileindex than having .vrt file referring to same originals as an input.  Things could have changed, and because your system is utilising overviews the originals will be opened only when zoomed in rather close and there is perhaps not so much .vrt file interpretation needed.

If Mapserver still happens to be faster with tileindex than .vrt, how about making an tileindex overview builder utility for Mapserver, and add support of utilising tileindex overviews somehow directly, without grouping scale depentent layers?  GROUP layers are not very nice with WMS usage because also the component layers are advertised by the service, not only the group.

-Jukka Rahkonen-

> -----Alkuperäinen viesti-----
> Lähettäjä: mapserver-users-bounces at lists.osgeo.org 
> [mailto:mapserver-users-bounces at lists.osgeo.org] Puolesta BrainDrain
> Lähetetty: 17. helmikuuta 2010 10:31
> Vastaanottaja: mapserver-users at lists.osgeo.org
> Aihe: [mapserver-users] Re: Help (tips&tricks) on raster 
> datasetoptimization
> 
> 
> I'm usinng next steps:
> //translating source tiles
> gdal_translate.exe -of GTiff -co COMPRESS=DEFLATE -co TILED=YES
> "\\server\Tiles\tile1_1.tif" "c:\Tiles\tile1_1.tif"
> ....
> //building virtual table
> gdalbuildvrt -resolution average mosaic.vrt c:\Tiles\*.tif
> //adding overviews
> gdaladdo -r average --config INTERLEAVE_OVERVIEW PIXEL --config
> COMPRESS_OVERVIEW DEFLATE mosaic.vrt 2 4 8 16
> //mapserver map file:
> LAYER
>   STATUS ON
>   NAME "quickbird2008"
>   TYPE RASTER
>   DATA "../data/tiles/mosaic.vrt"
> ...
> Works great!
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