<div dir="ltr"><div><div>Hi,<br><br></div>I think you can find a lot of tutorial/cours on the grass website (under Documentation: <a href="http://grass.osgeo.org/documentation/tutorials/">http://grass.osgeo.org/documentation/tutorials/</a>), on the wiki (<a href="http://grasswiki.osgeo.org/wiki/Image_processing">http://grasswiki.osgeo.org/wiki/Image_processing</a>) and also on the manual page (<a href="http://grass.osgeo.org/grass64/manuals/index.html">http://grass.osgeo.org/grass64/manuals/index.html</a>). There are usually link to the man page for every command, with everything explained ;)<br>
<br><br></div>for your job (identify roadways), I think you will mostly be interrested by:<br>- Combined radiometric/geometric (segmentation based) supervised classification (i.gensigset, i.smap) <br><div>- i.segment (<a href="http://grass.osgeo.org/grass70/manuals/i.segment.html">http://grass.osgeo.org/grass70/manuals/i.segment.html</a>) working in grass7 ...<br>
</div><div><br><br></div><div>Sylvain<br></div><div><br><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2014-01-29 Pedro Camargo <span dir="ltr"><<a href="mailto:veigacamargo@gmail.com" target="_blank">veigacamargo@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div link="blue" vlink="purple" lang="EN-US"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks, Jiao!! This helps a lot!!!<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 style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Pedro<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 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"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Jiao Wang [mailto:<a href="mailto:jiao@hawaii.edu" target="_blank">jiao@hawaii.edu</a>] <br>
<b>Sent:</b> Tuesday, January 28, 2014 1:02 PM<br><b>To:</b> Pedro Camargo<br><b>Cc:</b> GRASS user list<br><b>Subject:</b> Re: [GRASS-user] Processing NAIP images<u></u><u></u></span></p><div><div class="h5"><p class="MsoNormal">
<u></u> <u></u></p><div><p class="MsoNormal">Hi Pedro,<u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">I did a test run and created an unsupervised classification image.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Here are the steps I did:<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">1 MrSID to tiff in QGIS<u></u><u></u></p>
</div><div><p class="MsoNormal">2 import tiff in GRASS (i.in.gdal)<u></u><u></u></p></div><div><p class="MsoNormal">3 create group and subgroup (i.group ---check "Define also sub-group(same name as group)"--- in the "Layers in selected group" keep one band file as described in i.cluster manual)<u></u><u></u></p>
</div><div><p class="MsoNormal">4 classification --signature(i.cluster)<u></u><u></u></p></div><div><p class="MsoNormal">5 classification--map (i.maxlik)<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p>
</div><div><p class="MsoNormal">Hope it helps.<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Best,<u></u><u></u></p></div><div><p class="MsoNormal">Jiao<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p><div><p class="MsoNormal">On Tue, Jan 28, 2014 at 9:00 AM, Pedro Camargo <<a href="mailto:veigacamargo@gmail.com" target="_blank">veigacamargo@gmail.com</a>> wrote:<u></u><u></u></p>
<div><div><div><div><div><div><div><p class="MsoNormal">Hi,<u></u><u></u></p></div><p class="MsoNormal" style="margin-bottom:12.0pt"> I am trying to generate land use maps (looking to identify roadways only, actually) using NAIP imagery.<br>
<br> Since I am using the pre-compiled GRASS, I do not have MrSID inside GRASS, so converted the images to TIFF using QGIS.<u></u><u></u></p></div><p class="MsoNormal" style="margin-bottom:12.0pt"> I believe I can use i.maxlik or something like that, but I do not know how to start. It keeps asking for groups, but I do not know what is a group image.<u></u><u></u></p>
</div><p class="MsoNormal"> <u></u><u></u></p></div><p class="MsoNormal" style="margin-bottom:12.0pt"> I googled a lot on this and looked into several tutorials, but still did not figure out how to start this. I have been educating myself through a few papers, but I guess I still need to find a good summarized tutorial on how to do this with multi band images such as NAIP.<u></u><u></u></p>
</div><p class="MsoNormal" style="margin-bottom:12.0pt">Does anybody have ideas to help?<u></u><u></u></p></div><p class="MsoNormal">Thanks,<br><br>Pedro<u></u><u></u></p></div><p class="MsoNormal"><br>_______________________________________________<br>
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