<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
<title></title>
</head>
<body text="#000000" bgcolor="#ffffff">
Hi Hakon,<br>
<br>
The gdal-tool "gdaltindex" generates a shapefile with the boundaries
of the rasters. (See <a class="moz-txt-link-freetext" href="http://www.gdal.org/gdaltindex.html">http://www.gdal.org/gdaltindex.html</a>) In a
second step you can generate a virtual raster with the tool
"gdalbuildvrt". This way all 95 rasters are still separate in the
file system, but for the GIS it appears as a single file. (see
<a class="moz-txt-link-freetext" href="http://www.gdal.org/gdalbuildvrt.html">http://www.gdal.org/gdalbuildvrt.html</a>).<br>
<br>
For performance reasons it is also recommended to build pyramids in
all individual rasterfiles. You can use gdaladdo for this purpose
(<a class="moz-txt-link-freetext" href="http://www.gdal.org/gdaladdo.html">http://www.gdal.org/gdaladdo.html</a>).<br>
<br>
I think this is the easiest solution to your problem and it doesn't
require scripting. It also works across several GIS, incl. QGIS,
Mapserver, gvSig, etc.<br>
<br>
In QGIS, there is a GUI to most of the GDAL-tools. The plugin is
called "GdalTools". After installation there is an additional menu
called "Raster". The gdalado command is called "Build Overviews".
The "gdalbuildvrt" command is called "Build virtual raster
catalogue". There is no equivalent to the first step, the
"gdaltindex" command, though.<br>
<br>
----<br>
<br>
Actually it came to my mind that it would be very convenient if the
GDAL-tools would allow a combined version of these three commands
from one single GUI. Your problem is very common, so I think many
people would benefit from such an additional tool, that would
automatically build pyramids, the tindex and the virtual raster, in
a single step.<br>
<br>
Hope this helps,<br>
Andreas<br>
<br>
On 1/24/11 4:38 PM, HÅKON BORCH wrote:
<blockquote cite="mid:81A97C4D-EEC6-42BD-B533-030F0DFAFA1E@me.com"
type="cite"><span class="Apple-style-span" style="font-family:
monospace;">Helo</span><span class="Apple-style-span"
style="font-family: monospace;"><br>
</span><span class="Apple-style-span" style="font-family:
monospace;">I have a catalog of 95 rasters with DEM. Each time
I want to use them I have to load a lot of them to find the one
I need that covers the area I am interested in. Is there a way
to generate a layer containing polygons of the extent of each
layer. I want to make this layer to easy find which DEM i should
load to a project.</span><span class="Apple-style-span"
style="font-family: monospace;"><br>
</span><span class="Apple-style-span" style="font-family:
monospace;"><br>
</span><span class="Apple-style-span" style="font-family:
monospace;">Or is there an other smart way to deal with a lot of
heavy raster files, without waitng and waiting and waiting for
them to render.</span><span class="Apple-style-span"
style="font-family: monospace;"><br>
</span><span class="Apple-style-span" style="font-family:
monospace;">Best</span><span class="Apple-style-span"
style="font-family: monospace;"><br>
</span><span class="Apple-style-span" style="font-family:
monospace;">Håkon Borch</span>
<pre wrap="">
<fieldset class="mimeAttachmentHeader"></fieldset>
_______________________________________________
Qgis-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Qgis-user@lists.osgeo.org">Qgis-user@lists.osgeo.org</a>
<a class="moz-txt-link-freetext" href="http://lists.osgeo.org/mailman/listinfo/qgis-user">http://lists.osgeo.org/mailman/listinfo/qgis-user</a>
</pre>
</blockquote>
<br>
</body>
</html>