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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Hi Jukka,<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">I finally managed to check up on your suggestion. I set the RESAMPLE mode to NEAREST in the mapfile on a MapServer instance running locally on my machine.
This results in the same response as setting the resampling method in the url (see my previous email) :<br>
<br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"><a href="http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196396.75)&subset=y(450031.75,450031.75)">http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196396.75)&subset=y(450031.75,450031.75)</a></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"><?xml version="1.0" encoding="UTF-8"?></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"><ows:ExceptionReport xmlns:ows="<a href="http://www.opengis.net/ows/2.0">http://www.opengis.net/ows/2.0</a>" xmlns:xsi="<a href="http://www.w3.org/2001/XMLSchema-instance">http://www.w3.org/2001/XMLSchema-instance</a>"
version="2.0.1" xml:lang="en-US" xsi:schemaLocation="<a href="http://www.opengis.net/ows/2.0%20https:/geodata.nationaalgeoregister.nl/ows/2.0/owsExceptionReport.xsd">http://www.opengis.net/ows/2.0 https://geodata.nationaalgeoregister.nl/ows/2.0/owsExceptionReport.xsd</a>"></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"> <ows:Exception exceptionCode=""></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"> <ows:ExceptionText>msImageCreate(): Image handling error. Attempt to allocate raw image failed, out of memory.</ows:ExceptionText></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"> </ows:Exception></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"></ows:ExceptionReport></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Also all resampling methods result in the same response (tested by supplying through the query parameter in the url). When I look in the logs I see
that MapServer determines the dimensions of the request to be 0x0 pixels, causing the creation of the image to fail:<br>
<br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">2020-05-06 17:38:11: (mod_fastcgi.c.421) FastCGI-stderr: Subset for X-axis found: x</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">2020-05-06 17:38:11: (mod_fastcgi.c.421) FastCGI-stderr: Subset for Y-axis found: y</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">2020-05-06 17:38:11: (mod_fastcgi.c.421) FastCGI-stderr: msWCSGetCoverage20(): Set parameters from originaldata. Width: 0, height: 0, cellsize: -nan, extent: -nan,-nan,-nan,-nan</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">2020-05-06 17:38:11: (mod_fastcgi.c.421) FastCGI-stderr: msImageCreate(): Image handling error. Attempt to allocate raw image failed, out of memory.</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Arial",sans-serif"></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">I also quickly checked whether requesting a 1x1 subset works, but this fails by returning geotiff
image of 1x1 pixel with a pixel size of "-135000,162500":<br>
<a href="http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196397.25)&subset=y(450031.75,450032.25)">http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196397.25)&subset=y(450031.75,450032.25)</a><o:p></o:p></span></p>
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However requesting an image of 2x2 pixels still works as expected:<br>
<a href="http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196397.75)&subset=y(450031.75,450032.75)">http://localhost:32788/ahn3/wcs?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=ahn3_05m_dsm&format=image/tiff&subset=x(196396.75,196397.75)&subset=y(450031.75,450032.75)</a><span style="color:black"><o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">Kind regards,<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">Anton</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="color:black">From:</span></b><span lang="EN-US" style="color:black"> Rahkonen Jukka (MML) <<a href="mailto:jukka.rahkonen@maanmittauslaitos.fi">jukka.rahkonen@maanmittauslaitos.fi</a>><br>
<b>Sent:</b> Tuesday, April 7, 2020 5:49 PM<br>
<b>To:</b> Bakker, Anton <<a href="mailto:Anton.Bakker@kadaster.nl">Anton.Bakker@kadaster.nl</a>>;
<a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a> <<a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a>><br>
<b>Subject:</b> Re: WCS GetCoverage request one by one pixel</span><span lang="EN-US">
<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <o:p></o:p></span></p>
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<p class="xmsonormal"><span lang="FI">Hi Anton,<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="FI"> <o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">What I meant was to have a try by commenting out this line from your mapfile</span><span lang="FI"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas"> PROCESSING "RESAMPLE=BILINEAR"</span><span lang="FI"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas"> </span><span lang="FI"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas">Actually it would be interesting to know what really happens if the interpolation/resampling method is configured in the mapfile and GetCoverage comes also with Interpolation
parameter.</span><span lang="FI"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas"> </span><span lang="FI"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="FI">-Jukka-<o:p></o:p></span></p>
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