[Mapserver-users] ECW files

[Richard Greenwood]

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At 11:42 AM 1/28/2003 +1030, you wrote:

>Greetings all,
>
>I'd like to use an ecw file in a Mapserver application and need some
>clues.
>
>I'm using Mapserver 3.6 binary on a Windows NT box.  It's all running
>happily, though all files are presented unprojected.
>
>Firstly, http://www.remotesensing.org/gdal/frmt_ecw.html doco says
>maximum ecw filesize is 500MB, and the dataset is larger than that.
>Any clues on software that can uncompress, clip and recompress?

http://www.ermapper.com/ has free uncompress and compress tools. The viewer 
(which does the uncompression) can write out a world file. GRASS is my 
choice for clipping or tiling. And I think there are some performance 
advantages in using a tiled set of images even when using sophisticated 
compression like ECW or MrSID.



>Secondly, doco says certain SDK dll's are required and suggests
>location in the 'same directory as the GDAL DLL'. I found the SDK
>library, but I can't find the GDAL DLL on my machine.  Where does the
>GDAL come from?

http://www.remotesensing.org/gdal/


>Thirdly, I'm worried about projection.  The ecw is in UTM Zone 53
>South GDA94 (=WGS84 horizontally) and I want to project to Albers,
>already configured.  I this object adequate:

Be sure you set Albers in the main section of your map file (outside of a 
layer definition). You might consider reprojecting from UTM to Albers when 
you tile.


>LAYER
>      NAME "mtlofty_ecw"
>      DATA "MtLoftyRanges.ecw"
>      TYPE RASTER
>      STATUS ON
>      PROJECTION
>         "proj=utm"
>         "ellps=WGS84"
>         "datum=WGS84"
>         "units=m"
>         "zone=53"
>         "south"
>         "no_defs"
>     END
>END
>
>?
>
>Regards,
>
>Lyndon Z
>Adelaide, Australia
>_______________________________________________
>Mapserver-users mailing list
>Mapserver-users at lists.gis.umn.edu
>http://lists.gis.umn.edu/mailman/listinfo/mapserver-users

Richard W. Greenwood, PLS
(307) 733-0203
Rich at GreenwoodMap.com
www.GreenwoodMap.com 

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