Hello Nikos, 2013/11/27 Nikos Alexandris <[email protected]>
> Cesar Augusto Ramírez Franco wrote: > > > Hello everyone, > > Hello, > > > > I've been trying to do a supervised classification from landsat8 imagery > > using i.class and then i.maxlik, but I'm getting an error when running > > i.maxlik saying it can't read the signature file. > > Just to double-check: verify that your "classes" don't overlay any NULL > cells. > It might be completely irrelevant, I have, though, blurry memories of this > being a blocker actually (with i.smap at least). There are no NULL cells on my classes, neither on my Landsat 8 images or the Landsat 7 in the North Carolina dataset > I tested my procedure on the NC sample dataset and I'm getting the same > > error, I'm using Grass 6.4.2 on Debian Wheezy, installed from the debian > > repo. Here's the command set: > > > #Display RGB enhanced map > > i.landsat.rgb blue=lsat7_2000_10 green=lsat7_2000_20 red=lsat7_2000_30 > > d.rgb blue=lsat7_2000_10 green=lsat7_2000_20 red=lsat7_2000_30 > > > #"Real color" map > > r.composite red=lsat7_2000_30 green=lsat7_2000_20 blue=lsat7_2000_10 > > output=lsat7_2000_RGB > > > #Group images to process > > i.group group=lsat7_2000_RGB subgroup=lsat7_2000_RGB > > input=lsat7_2000_10,lsat7_2000_20,lsat7_2000_30 > > > #Unsupervised classification > > i.cluster group=lsat7_2000_RGB subgroup=lsat7_2000_RGB sigfile=clustlsat7 > > classes=20 report=rep_clust_lsat7.txt > > (I have never tried to feed a group that uses a single composite. I'll try > it > out.) > The composite is for the supervised clasification, the group and subgroup are made with the 3 RGB bands (1,2,3 in Landsat7 or 2,3,4 in Landsat8) > i.maxlik group=lsat7_2000_RGB subgroup=lsat7_2000_RGB sigfile=clustlsat7 > > class=lsat7_classes reject=lsat7_classes_rej > > Does the unsupervised classification work? i.cluster requires at least two > input raster maps. And, honestly, I have never tried it the way you did, > i.e. > by using a composite map. Also, r.composite will use by default "32 > levels" > whicih means that you loose important info for the subsequent > classification, > if I am not wrong. The supervised classification does work, i.cluster generates a signature file and i.maxlik success to create the classes raster map > #Supervised classification > > i.class map=lsat7_2000_RGB group=lsat7_2000_RGB subgroup=lsat7_2000_RGB > > outsig=classlsat7 > > i.maxlik group=lsat7_2000_RGB subgroup=lsat7_2000_RGB sigfile=classlsat7 > > class=lsat7_class_sup > > > Here I get the error in which i.maxlik can't read the signature file > > created by i.class (classlsat7) but read the one created by i.cluster > > flawlessly > > > > This is what I'm selecting on the i.class monitor, I named it vegetation: > > [image: Imagen integrada 1] > > Only on class? Can you try with more please? > Yes, the error I'm getting is only with the i.class module I'm doing some tests creating a test vector with my classes as areas, then converting it to raster with v.to.rast, and then using that raster to generate statistics for i.smap with i.gensigset I don't know if I'm not using the i.class module the right way or if it's broken > And the contents of the classlsat7 signature file are the following: > > > > # > > > > #vegetation > > > > 166 > > > > Am I doing something wrong or is it some kind of bug? > > Greets, Nikos > Thank you very much -- *César Augusto Ramírez Franco* Laboratorio de Sistemas Complejos Naturales Escuela de Geociencias Facultad de Ciencias Universidad Nacional de Colombia - Sede Medellín Teléfono: (57-4) 430 9369 - 301 389 5607
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
