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</o:shapelayout></xml><![endif]--></head><body lang=DE link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText><span lang=EN-US>Dear Jukka,<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>thank you for your answer.<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>I still don’t know how to build pyramids just for defined scale ranges (in my case: smaller then 1:25.000).<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>I’ve forgotten to tell you an –maybe important- detail: I’m working with a virtual raster catalogue which i built out of 875 .jpgs (4000x4000).<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>When building pyramids, i’ve always used the option “external (Erdas Image.aux)”.<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Can you shortly explain the difference between the 3 options (external .ovr, internal, external .aux)?<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>I couldn’t find an advice in the handbook or via google.<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>The QGIS instructions say that after building pyramids QGIS automaticly takes the best resolution when loading raster layers. So how can I influence what resolution QGIS chooses?<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><br>Thanks again for further help!<br><br>Kind regards,<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><br>Julian Schall<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>Date: Thu, 12 Jun 2014 09:34:18 +0000 (UTC)<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>From: Jukka Rahkonen <</span><a href="mailto:jukka.rahkonen@mmmtike.fi"><span lang=EN-US>jukka.rahkonen@mmmtike.fi</span></a><span lang=EN-US>><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>To: </span><a href="mailto:qgis-user@lists.osgeo.org"><span lang=EN-US>qgis-user@lists.osgeo.org</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Subject: Re: [Qgis-user] QGIS: Reduction of resolution via pyramids<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US> only for defined scale range<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Message-ID: <</span><a href="mailto:loom.20140612T112229-91@post.gmane.org"><span lang=EN-US>loom.20140612T112229-91@post.gmane.org</span></a><span lang=EN-US>><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Content-Type: text/plain; charset=utf-8<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>Julian Schall <</span><a href="mailto:j.schall@..."><span lang=EN-US>j.schall@...</span></a><span lang=EN-US>> writes:<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>> <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> Hello members of the mailing list, <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> ?<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> I would appreciate help on the following problem: <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> I would like to improve the performance of a raster layer. Of course I can<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>build pyramids for that purpose. But in the scale ranges from 1:1 to<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>1:25.000 I need maximum resolution and detail. In this scale range, the<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>performance is sufficient even without pyramids. <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> Ideal would be that the pyramids respectively the reduction of the<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>resolution with improvement of performance is only applied to scales smaller<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>than 1:25,000. Is this possible in QGIS? <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> ?<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> Thanks for helpful answers! <o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> ?<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>> Kind regards <o:p></o:p></span></p><p class=MsoPlainText>> ?<o:p></o:p></p><p class=MsoPlainText><span lang=EN-US>> Julian Schall<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>There are check boxes for overview levels in the Build overviews panel.<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Level 2 means double the original pizel size etc. Leave for example levels 2<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>and 4 unchecked. However, level 2 means 25% extra disk space but level 4<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>only 6.25%. Thus it may not make sense to skip other levels than 2. Remember<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>to compress also the overviews and test with external overviews which you<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>can easily delete and continue with new tests. Internal overviews can be<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>removed so that they are no more used but operation does not make image<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>files smaller.<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>------------------------------<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>_______________________________________________<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Qgis-user mailing list<o:p></o:p></span></p><p class=MsoPlainText><a href="mailto:Qgis-user@lists.osgeo.org"><span lang=EN-US>Qgis-user@lists.osgeo.org</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoPlainText><a href="http://lists.osgeo.org/mailman/listinfo/qgis-user"><span lang=EN-US>http://lists.osgeo.org/mailman/listinfo/qgis-user</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>