<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>I think you are referring to XYZ tiles which are 256x256 pixels.
These are designed to be put onto a web server and served through
WMTS to a client. Is that the kind of application you are using
them in?</p>
<div class="moz-cite-prefix">On 29/09/22 01:22, Michael.Dodd wrote:<br>
</div>
<blockquote type="cite"
cite="mid:LO2P265MB3406EDB9FE383DC290BF923BB0549@LO2P265MB3406.GBRP265.PROD.OUTLOOK.COM">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="Generator" content="Microsoft Word 15 (filtered
medium)">
<style>@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
font-size:10.0pt;
font-family:"Courier New";
mso-fareast-language:EN-GB;}span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:"Consolas",serif;
mso-fareast-language:EN-US;}span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}div.WordSection1
{page:WordSection1;}</style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal">You can see the format via the link (shown
in more detail here
<a
href="https://osdatahub.os.uk/downloads/open/Terrain50?_gl=1*19hd950*_ga*MTM1NTcyMjQ5MC4xNjY0MzY3NTYw*_ga_59ZBN7DVBG*MTY2NDM2NzU2MC4xLjAuMTY2NDM2NzU2MS41OS4wLjA.&_ga=2.219085721.1292185665.1664367560-1355722490.1664367560"
moz-do-not-send="true">
OS Terrain® 50 | OS Data downloads | OS Data Hub</a>) they
are ascii grid basically numbers so should not have any .jpg
issues. It is unfortunate that they chose to make the grid
file so difficult to use by chopping it into the many
thousands of small squares each within its own folder within
other folders within other folder.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal"><b><span
style="mso-fareast-language:EN-GB" lang="EN-US">From:</span></b><span
style="mso-fareast-language:EN-GB" lang="EN-US">
Qgis-user <a class="moz-txt-link-rfc2396E" href="mailto:qgis-user-bounces@lists.osgeo.org"><qgis-user-bounces@lists.osgeo.org></a>
<b>On Behalf Of </b>Patrick Dunford via Qgis-user<br>
<b>Sent:</b> Wednesday, September 28, 2022 1:14 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</a><br>
<b>Subject:</b> Re: [Qgis-user] large DEM not loading
tiles correctly<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="mso-element:para-border-div;border:solid black
1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt;background:#FFFFCC">
<p style="background:#FFFFCC;border:none;padding:0cm"><span
style="font-family:"Arial",sans-serif;color:black">CAUTION:
This mail comes from outside the University. Please
consider this before opening attachments, clicking links,
or acting on the content.
</span><span
style="font-family:"Arial",sans-serif;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
</div>
<div>
<p>Hello<o:p></o:p></p>
<p>This is a raster format? and how large are the tiles?<o:p></o:p></p>
<p>I spend a lot of time working with raster files often a few
thousand at a time. There doesn't seem to be a problem
displaying them in Qgis unless they are Progressive Jpeg
format, which in more recent years seem to have an issue
with one of the third party libraries Qgis uses to import
with. <o:p></o:p></p>
<div>
<p class="MsoNormal">On 29/09/22 00:32, Michael.Dodd via
Qgis-user wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">I am trying to put together the 50m uk
DEM e.g. <a
href="https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.data.gov.uk%2Fdataset%2F835cf20a-8feb-4394-8b30-dcfe840ac13d%2Fos-terrain-50-dtm&data=05%7C01%7Cmichael.dodd%40open.ac.uk%7Ce252ba17960e47d4459b08daa14af7f3%7C0e2ed45596af4100bed3a8e5fd981685%7C0%7C0%7C637999640602880359%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=0kauz1XTDogmzS2bswO60uWR2EgvdVNCSOPzTKC3pjo%3D&reserved=0"
moz-do-not-send="true">
https://www.data.gov.uk/dataset/835cf20a-8feb-4394-8b30-dcfe840ac13d/os-terrain-50-dtm</a>
but it often does not work. The data are supplied as
thousands of small tiles that takes ages to unpack and put
into a folder to get into qgis, however when you try to
load the tiles some work and others don’t and even the
ones that do work and display fine sometimes don’t merge
to form large tiles and sometimes will form virtual
rasters but not merged files. Basically it is a mess. I
suspect others have done this successfully so any
suggestions?<o:p></o:p></p>
<p class="MsoNormal">It is particularly odd that some of the
tiles will merge and others won’t and that some won’t
display if you ask it to load hundreds at a time but if
you just add them in a few at a time then they will load
and display (in addition to the hundreds already loaded).
This suggests various bugs assuming the original data are
not in a whole variety of slightly different formats
(should all be .asc)<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><span
style="mso-fareast-language:EN-GB"><br>
<br>
<o:p></o:p></span></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Qgis-user mailing list<o:p></o:p></pre>
<pre><a href="mailto:Qgis-user@lists.osgeo.org" moz-do-not-send="true" class="moz-txt-link-freetext">Qgis-user@lists.osgeo.org</a><o:p></o:p></pre>
<pre>List info: <a href="https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.osgeo.org%2Fmailman%2Flistinfo%2Fqgis-user&data=05%7C01%7Cmichael.dodd%40open.ac.uk%7Ce252ba17960e47d4459b08daa14af7f3%7C0e2ed45596af4100bed3a8e5fd981685%7C0%7C0%7C637999640602880359%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=MfUB29jeUKq7aYE6vxximvyxl1YHm1EBwytOfT42Xjc%3D&reserved=0" moz-do-not-send="true">https://lists.osgeo.org/mailman/listinfo/qgis-user</a><o:p></o:p></pre>
<pre>Unsubscribe: <a href="https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.osgeo.org%2Fmailman%2Flistinfo%2Fqgis-user&data=05%7C01%7Cmichael.dodd%40open.ac.uk%7Ce252ba17960e47d4459b08daa14af7f3%7C0e2ed45596af4100bed3a8e5fd981685%7C0%7C0%7C637999640602880359%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=MfUB29jeUKq7aYE6vxximvyxl1YHm1EBwytOfT42Xjc%3D&reserved=0" moz-do-not-send="true">https://lists.osgeo.org/mailman/listinfo/qgis-user</a><o:p></o:p></pre>
</blockquote>
</div>
</div>
</blockquote>
</body>
</html>