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<p class="MsoNormal">I am soooo happy today! <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I discovered that starting with v2.10.24 Gimp knows about and keeps geotiff tags intact.[0] This means we can use tools like Magic Wand fuzzy select and a host of other tools to quickly fix a host of image issues that are difficult to address
using command line tools and/or code. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The big one for me at the moment is dealing with the artifact fringes introduced on image edges when people use jpeg compression.[1] Nearblack is something I keep constantly close by, but it can’t deal with areas that are blocked by horizontal
scanning.[2] Today I used Gimp to fix the nodata area for 5.5 GB spot image in about 20 minutes, including time with experimentation. True it needed ~45 GB of memory[3] so this isn’t something I’ll be doing at home, but it worked! [4] And I didn’t need to
fart around afterwards restoring georeferencing.[5]<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[0]: <a href="https://www.gimp.org/news/2021/03/29/gimp-2-10-24-released/">
https://www.gimp.org/news/2021/03/29/gimp-2-10-24-released/</a><o:p></o:p></p>
<p class="MsoNormal">[1]: <a href="https://i.imgur.com/LZNn5Zt.png">https://i.imgur.com/LZNn5Zt.png</a><o:p></o:p></p>
<p class="MsoNormal">[2]: <a href="https://i.imgur.com/avkILmX.png">https://i.imgur.com/avkILmX.png</a><o:p></o:p></p>
<p class="MsoNormal">[3]: <a href="https://i.imgur.com/DVLK1OB.png">https://i.imgur.com/DVLK1OB.png</a><o:p></o:p></p>
<p class="MsoNormal">[4] <a href="https://i.imgur.com/KRfxM0G.png">https://i.imgur.com/KRfxM0G.png</a><o:p></o:p></p>
<p class="MsoNormal">[5]: <a href="https://gis.stackexchange.com/a/115560">https://gis.stackexchange.com/a/115560</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Some post processing is needed to get things up to our local preferences, for instance Gimp’s alpha channel is 15-20% larger than a gdal external mask and it doesn’t know my new favourite compression method of ZSTD, but this is a huge step
forward. I could jump for joy, and maybe after I send this message I will ;-)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-top:4.0pt;line-height:115%;text-autospace:none;vertical-align:middle">
<b><span lang="EN-US" style="font-size:10.0pt;line-height:115%;mso-fareast-language:EN-CA">Matt Wilkie</span></b><span lang="EN-US" style="font-size:10.0pt;line-height:115%;mso-fareast-language:EN-CA"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;mso-fareast-language:EN-CA">Geomatics Developer & Administrator<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;mso-fareast-language:EN-CA">Environment
<span style="color:#2E74B5">|</span> Technology, Innovation and Mapping<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;mso-fareast-language:EN-CA">T 867-667-8133
<span style="color:#2E74B5">|</span> </span><u><span style="font-size:10.0pt;mso-fareast-language:EN-CA"><a href="http://yukon.ca/"><span lang="EN-US" style="color:windowtext">Yukon.ca</span></a><o:p></o:p></span></u></p>
<p class="MsoNormal"><i><span style="font-size:10.0pt;mso-fareast-language:EN-CA">Hours: 08:30-16:30, Mon-Wed: Office, Thu: Remote, Fri: Away.<o:p></o:p></span></i></p>
<p class="MsoNormal"><o:p> </o:p></p>
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