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<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2>Jordi -</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2>You said you wanted to "avoid the use of tile indexes or
catalogues of images", but isn't that exactly what your XML catalogue/index
does? It seems that the GeoQuadTree format is a different form of that
same sort of structure. There are several different ways of doing this
now, including the TILEINDEX mechanism, tiled TIFF files, etc. I'm sure
there are limitations to each, but I'm not sure that yet another tiling scheme
will help.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2>In particular, PNG is not the best format for all images,
and it's important to support other encoding mechanisms, especially JPEG.
Photographic images are huge when stored in PNG format, and JPEG is usually a
much better choice. Conversely, scanned line art and synthetic images
generally compress and store better as PNG images.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006> <FONT
face=Arial color=#0000ff size=2>- Ed</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=804023220-14112006>
<P><FONT size=2>Ed McNierney<BR>President and Chief Mapmaker<BR>TopoZone.com /
Maps a la carte, Inc.<BR>73 Princeton Street, Suite 305<BR>North Chelmsford,
MA 01863<BR>ed@topozone.com<BR>(978) 251-4242 </FONT></P></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> gdal-dev-bounces@lists.maptools.org
[mailto:gdal-dev-bounces@lists.maptools.org] <B>On Behalf Of </B>Brent
Fraser<BR><B>Sent:</B> Tuesday, November 14, 2006 3:05 PM<BR><B>To:</B> Jordi
Gilabert Vall; gdal-dev@lists.maptools.org<BR><B>Subject:</B> Re: [Gdal-dev]
GeoQuadTree - an open format for storinggeoreferencedimages<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT size=2>For those interested tiling,</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2> There is similar tiling related discussion/work
going on at:</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2> <A
href="http://lists.eogeo.org/mailman/listinfo/tiling"><FONT
size=3>http://lists.eogeo.org/mailman/listinfo/tiling</FONT></A> (do they
have a web page?)</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2> and </FONT></DIV>
<DIV><FONT size=2> <A
href="http://www.stereofx.org/terrain.html">http://www.stereofx.org/terrain.html</A>,
implemented in <A href="http://vterrain.org/">http://vterrain.org/</A>,
particularly VTBuilder (<A
href="http://vterrain.org/Doc/VTBuilder/overview.html">http://vterrain.org/Doc/VTBuilder/overview.html</A>)</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Brent Fraser</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jordi@geoquadtree.org href="mailto:jordi@geoquadtree.org">Jordi
Gilabert Vall</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=gdal-dev@lists.maptools.org
href="mailto:gdal-dev@lists.maptools.org">gdal-dev@lists.maptools.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, November 14, 2006 3:25
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [Gdal-dev] GeoQuadTree - an open
format for storing georeferencedimages</DIV>
<DIV><BR></DIV>Hi,<BR><FONT face="Arial, sans-serif"><FONT size=2><BR>Some
time ago I needed the retrieval from very large georeferenced raster images in
a OGC WMS server, and I wanted to avoid the use of tile indexes or catalogues
of images, neither a database. I started thinking of an open format for
storing arbitrarily large georeferenced images. I named this format
"GeoQuadTree", as it would be based on a quadtree of rectangular tiles, each
in PNG format on the filesystem, in a simple hierarchical structure of
folders. I wrote a command line utility for creating it, importing from
PNG/JPEG/TIFF and exporting to PNG/JPEG/TIFF/GDAL. I also wrote a GDAL driver
for this format. I tested successfully with my own WMS server software, and on
MapServer compiled with GDAL support. It worked very well on Blue Marble Next
Generation at a resolution of 15 arc-seconds, i.e. 86400x43200
pixels.</FONT></FONT>
<P style="MARGIN-BOTTOM: 0cm"><FONT face="Arial, sans-serif"><FONT size=2>You
can find more information on the project web site:</FONT></FONT></P>
<P style="MARGIN-BOTTOM: 0cm; MARGIN-LEFT: 40px"><FONT
face="Arial, sans-serif"><FONT size=2><A
onclick="return top.js.OpenExtLink(window,event,this)"
href="http://geoquadtree.org/" target=_blank>http://geoquadtree.org/
</A></FONT></FONT></P>
<P style="MARGIN-BOTTOM: 0cm"><FONT face="Arial, sans-serif"><FONT size=2>I'm
testing the release 1.0.0, you can test it on the subversion repository if you
want (I haven't packaged it yet).<BR></FONT></FONT></P>
<P style="MARGIN-BOTTOM: 0cm"><FONT face="Arial, sans-serif"><FONT size=2>I
think it's a useful format, open, very easy to use, and very efficient (in
terms of response time).</FONT></FONT></P>
<P style="MARGIN-BOTTOM: 0cm"><FONT face="Arial, sans-serif"><FONT size=2>Do
you think it could be useful for you ? Would you like to include it on GDAL's
next release ?</FONT></FONT></P><SPAN class=sg>
<P style="MARGIN-BOTTOM: 0cm"><FONT face="Arial, sans-serif"><FONT
size=2>jordi at geoquadtree org</FONT></FONT></P></SPAN>
<P>
<HR>
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