Serving MrSidd images

[Larry Shaffer]

Lawrence,

You can download the LizardTech MrSID Decode program and make your MrSID
files into GeoTIFFs.

http://www.lizardtech.com/download/dl_options.php?page=tools

To use GDAL with MrSID support, it has to be compiled in from the start
(using the SDK for MrSID). If you are using a prebuilt binary, this may
not be available. Your best bet is to turn them into GeoTIFFs, or, better
yet, search for original GeoTIFFs of your MrSID files - I have found
MrSID files to have too many artifacts in their compression. For example,
the compression applied to many USGS Aerial MrSID files is usually so
much that the quality is poorer than those generated by Terraserver! A
Mapserver-tiled 8-bit GeoTIFF should be better (than any compression
advantages MrSID supplies at high bit sizes) in quality when one zooms in
- in my opinion.

-- 
Larry




# Travis Kirstine GIS Tech <tkirstine at JDBARNES.COM> emailed the following
#   on Thu, Dec 8, 2005 at 2:56 PM (12:56 PM South Dakota, USA):

>Lawrence,
>If it is possible I would recommend converting your MrSid images to GeoTiff
>format and serving them up that way. We've tried using MrSid's and haven't
>had much luck perfomance wise
>Travis
>
>-----Original Message-----
>From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]On
>Behalf Of Lawrence Hartpence
>Sent: Thursday, December 08, 2005 12:56 PM
>To: MAPSERVER-USERS at LISTS.UMN.EDU
>Subject: [UMN_MAPSERVER-USERS] Serving MrSidd images
>
>
>Hello,
>
>I am very new to MapServer.  I wanted to add a set of tiled images in MrSidd
>format to my map.  I have a shapefile depicting the locations of the tiles.
>I understand that I need GDAL to make this happen.  I loaded MapServer using
>the MS4W download.  Do I have GDAL?  If I do, how do I use it.  Also I am
>running MapServer on a Windows 2000 server machine with IIS as the
>webserver.
>
>Lawrence Hartpence
>GIS Coordinator
>101 1st St N
>Newton IA 50208
>641-792-3084
>hartpence_gis at co.jasper.ia.us