<div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Feb 17, 2014 at 2:03 PM, Ivan Price <span dir="ltr"><<a href="mailto:Ivan.Price@noveltis.fr" target="_blank">Ivan.Price@noveltis.fr</a>></span> wrote:<br>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hi Etienne,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">firstly the problem reading the MERIS (actually coastcolour) data was due to the fact i was using gdal 1.6, after upgrading to 1.9 i can at least
list the bands so i guess that 'works'.</span></p></div></div></blockquote><div><br></div><div>does it really work or sort of? If not, please file a bug report with an example data set attached or a link to it.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="FR" link="blue" vlink="purple"><div><p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">regarding the use of the filesystem, i tried that, however it is slow to write out the whole dataset to disk, (i need to treat hundreds of images),
so i was looking for a way to avoid this.. although it will be my fallback option if all else fails..</span></p></div></div></blockquote><div><br></div><div>have you tried using a .vrt file?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="FR" link="blue" vlink="purple"><div><p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">either way i'll reply to the list with what we do in the end<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">thanks for your response,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">-i<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">De :</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Etienne Tourigny [mailto:<a href="mailto:etourigny.dev@gmail.com" target="_blank">etourigny.dev@gmail.com</a>]
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<b>Envoyé :</b> Monday, 17 February 2014 14:09<br>
<b>À :</b> Ivan Price<br>
<b>Cc :</b> <a href="mailto:gdal-dev@lists.osgeo.org" target="_blank">gdal-dev@lists.osgeo.org</a></span></p><div class=""><br>
<b>Objet :</b> Re: [gdal-dev] reprojecting coastcolour (/meris) using python via GCPs<u></u><u></u></div><p></p>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">As far as I know, the gdal warp api is not exposed to python.<u></u><u></u></p><div><div class="h5">
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I have no idea on reading the MERIS data with the gdal netcdf driver - what I the problem? <u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">But you might be able to use this workaround: instead of creating a source dataset using the memory driver, create a file on disk (in gtiff format) with GCPS and write data to disk, and then use gdalwarp on that.<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Etienne<u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p>
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<p class="MsoNormal">On Mon, Feb 17, 2014 at 6:46 AM, Ivan Price <<a href="mailto:Ivan.Price@noveltis.fr" target="_blank">Ivan.Price@noveltis.fr</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Hello,</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">I am trying to reproject a window inside a coastcolour (=MERIS) image. As far as I can see GDAL cannot read the coastcolour data directly, so i am reading the
coastcolour netcdf in python, building a source dataset using the memory driver, adding GCPS (1 for every 10th pixel) and writing the data to it, then reprojecting the source dataset to a destination dataset which is a spatial subset of the original in wgs84
lat/long.</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">This works fine and is relatively fast, but the reprojection is not accurate, the results are out by about 6-10 pixels (in various directions). On reading the
forums it seems if i was using gdalwarp i would be using -tps, however the ReprojectImage() function does not seem to offer this parameter ? And i don't have the option of using the commandline tool as even gdal 1.10 cannot recognise the coastcolour data.
</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">So i guess i have 2 questions.. has anyone had any success reading coastcolour data with the gdal command line tools, and secondly:
</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">how can i get ReprojectImage() to be more accurate, given i have a GCP for every pixel ?</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">thanks and regards,</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#888888"> </span><span style="color:#888888"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#888888">-ivan</span><span style="color:#888888"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#888888"> </span><span style="color:#888888"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#888888"> </span><span style="color:#888888"><u></u><u></u></span></p>
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