<div dir="auto">Yes, that is true. It happened to me once.<div dir="auto">What I mean is that the plain vanilla without all defaults (no overviews, no tiles) is currently manageable. Changing only the "tiled" default would make the vanilla case unmanageable. And some not expert users will complain.</div><div dir="auto"><br></div><div dir="auto">Maybe it is good to document that behavior.</div><div dir="auto"><br></div><div dir="auto">Btw, how spread is the support for tiled TIFFs among other viewers?</div><div dir="auto"><br></div><div dir="auto">Cheers</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">El mar., 30 nov. 2021 19:29, Rahkonen Jukka (MML) <<a href="mailto:jukka.rahkonen@maanmittauslaitos.fi">jukka.rahkonen@maanmittauslaitos.fi</a>> escribió:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span lang="EN-US">Hi,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">On the other hand those QGIS users pay the price every time when they zoom close to the same image because then QGIS must read many super wide rows of data instead of just the tiles
that intersect the view. Not even overviews which are created on top of striped image do not help when user hit the native resolution. But perhaps it is not so important what is the default, experienced users maybe know what they want.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">-Jukka Rahkonen-<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">Lähettäjä:</span></b><span lang="EN-US"> Javier Jimenez Shaw <<a href="mailto:j1@jimenezshaw.com" target="_blank" rel="noreferrer">j1@jimenezshaw.com</a>>
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<b>Lähetetty:</b> tiistai 30. marraskuuta 2021 11.09<br>
<b>Vastaanottaja:</b> Rahkonen Jukka (MML) <<a href="mailto:jukka.rahkonen@maanmittauslaitos.fi" target="_blank" rel="noreferrer">jukka.rahkonen@maanmittauslaitos.fi</a>><br>
<b>Kopio:</b> <a href="mailto:gdal-dev@lists.osgeo.org" target="_blank" rel="noreferrer">gdal-dev@lists.osgeo.org</a><br>
<b>Aihe:</b> Re: [gdal-dev] Should we make also GTiff to use TILED=YES as default?<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Hi Jukka<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">I don't think it is a good option.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">TL;DR: tiled without overviews is extremely slow for a global view.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">If you have a (big) image with TILED=YES but without overviews, it is really really slow in QGIS (from seconds to many minutes).<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">The reason (I guess) is that QGIS is by default sub-sampling the image using nearest neighbor. If the image is not tiled, then it has to read only every nth line. However, when tiled, at the end has to read the full image
from file.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">The bigger the zoom level, the faster it goes. But waiting 5 minutes to see the global view of your image to know where to zoom in... you close QGIS and blame somebody.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">That changes dramatically if there are (proper) overviews available, of course.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Cheers<u></u><u></u></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-US">.___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... .... ._ .__<br>
Entre dos pensamientos racionales <br>
hay infinitos pensamientos irracionales.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">On Tue, 30 Nov 2021 at 08:04, Rahkonen Jukka (MML) <</span><a href="mailto:jukka.rahkonen@maanmittauslaitos.fi" target="_blank" rel="noreferrer"><span lang="EN-US">jukka.rahkonen@maanmittauslaitos.fi</span></a><span lang="EN-US">> wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Hi,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">There are loads of questions in the stack.exchange site where users have problems with performance when they do something with reading and writing very large
image files. Big files have obviously become much more common now due to clouds. Users try to solve the problem by increasing GDAL_CACHEMAX and using multithreading etc. but they use the default GeoTIFF settings and keep on writing huge striped TIFFs. I wonder
if we should make tiling the default also for the GTiff driver like it is in the COG driver.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal">-Jukka Rahkonen-<u></u><u></u></p>
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