<br><font size=2 face="sans-serif">IMO:</font>
<br>
<br>
<br><font size=2 face="sans-serif">Hi Paul,</font>
<br>
<br><font size=2><tt><br>
> All too often, the "benefits" touted for raster-in-database
have <br>
> nothing to do with the database, and everything to do with the data
<br>
> preparation tools that the vendor is including with their raster-in-
<br>
> database solution.</tt></font>
<br><font size=2><tt>> <br>
> To store rasters in a database, you need a set of tools that will
(a) <br>
> chop the inputs into something small enough to fit on a database page
<br>
> (tiling), (b) pyramid the source data up so you don't have to run
re- <br>
> sampling operations on the fly, and (c) handle mosaicking operations
<br>
> at the edges of source input files.</tt></font>
<br>
<br>
<br><font size=2><tt>My preference is to use true image processing tools
for raster manipulation. ERMapper, Erdas, Envi etc. There are also a number
of Open Source tools that I've yet to explore.</tt></font>
<br>
<br><font size=2><tt>wrt mosaicing, Erdas has a nice tool that incorporates
aerotriangulation into the process.</tt></font>
<br>
<br><font size=2><tt><br>
</tt></font>
<br><font size=2><tt><br>
> <br>
> Here's how to do all of this stuff without the database:<br>
> <br>
> <br>
> > - store a relatively large amount imagery and utilise it as a
single <br>
> > entity (e.g. a layer).<br>
> <br>
> Use a web service to expose the data, such as WMS. You can view your
<br>
> WMS in ArcMap, in Google Earth, in a web browser typing in a URL with
<br>
> your toes.</tt></font>
<br>
<br>
<br><font size=2><tt>WMS is showing a lot of promise, particularly with
v1.3. I like the spec description of serving multispectral and multitemporal
imagery from the one service, allowing the user to specify image time and
bands to display.</tt></font>
<br>
<br><font size=2><tt><br>
> <br>
> Far more interoperable than raster-in-database client code, because
it <br>
> is far simpler.<br>
> <br>
> Using Mapserver, and a tile-indexed raster layer, you can publish
a <br>
> seamless view of as many source files as you like. (Chris Hodgson
did <br>
> it for over 1000 source files, see http://mapserver.gis.umn.<br>
> edu/community/conferences/MUM3/present/session2/hodgson/view)<br>
></tt></font>
<br>
<br>
<br><font size=2><tt>We have a wealth of choices. </tt></font>
<br>
<br><font size=2><tt>What it comes down to is what is appropriate for your
use case.</tt></font>
<br>
<br>
<br><font size=2><tt>Thanks again,</tt></font>
<br>
<br><font size=2><tt>Bruce</tt></font>
<br>
<br>
<br><font size=2><tt><br>
</tt></font>
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