<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Thanks,</div><div><br></div><div>I’m using the technique described at <a href="http://blog.mathieu-leplatre.info/drape-lines-on-a-dem-with-postgis.html">http://blog.mathieu-leplatre.info/drape-lines-on-a-dem-with-postgis.html</a></div><div><br></div><div>What would be small tiles in this context? 256x256? The raster I was testing against was ~1200x1200.</div><div><br></div><div>-ra</div><br><div><div>On 27 Aug 2014, at 16:19, Pierre Racine <<a href="mailto:Pierre.Racine@sbf.ulaval.ca">Pierre.Racine@sbf.ulaval.ca</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Elevation profile should be quite fast depending on how you tile your raster coverage. Smaller tiles make computation faster. Index them and make sure your query is actually using the index.<br><br>Pierre<br><br><blockquote type="cite">-----Original Message-----<br>From: <a href="mailto:postgis-users-bounces@lists.osgeo.org">postgis-users-bounces@lists.osgeo.org</a> [mailto:postgis-users-<br><a href="mailto:bounces@lists.osgeo.org">bounces@lists.osgeo.org</a>] On Behalf Of Rasmus Aveskogh<br>Sent: Friday, August 22, 2014 4:10 PM<br>To: <a href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</a><br>Subject: [postgis-users] Elevation profiles from rasters<br><br>Hi!<br><br>How hard/feasible would it be to implement elevation profile/drape line<br>functionality in PostGIS? Since PostGIS already depends on GDAL I assume<br>making use of the GDAL API would make this quite easy, such as in the Zoo-<br>Project service:<br><br><a href="http://www.zoo-project.org/trac/browser/trunk/zoo-project/zoo-">http://www.zoo-project.org/trac/browser/trunk/zoo-project/zoo-</a><br>services/gdal/profile/service.c<br><br>Providing functionality that could eventually be used for applications like:<br>http://www.zoo-project.org/site/ZooWebSite/Demo/GdalProfile (using the<br>code above)<br><br>I'm currently using an ad-hoc PostGIS-function to pull out elevation profiles<br>from my rasters, but it's quite slow and CPU intensive and as such does not<br>make a good fit as a backend service for a web application like the above.<br><br>-ra<br></blockquote>_______________________________________________<br>postgis-users mailing list<br><a href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</a><br>http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users<br></blockquote></div><br></body></html>