Hello Venka Thank you for your response
Unfortunately, I did rescale my lsat8 images to 8bit, however, I tested with North Carolina sample dataset which is Landsat 7 (8bit) and got the same error, so it must be something else, maybe i.class generating a wrong signature file? 2013/11/26 Venkatesh Raghavan <ragha...@media.osaka-cu.ac.jp> > Hi Augusto, > > > In GRASS-6.4.3, i.class only works on 8bit images. Since the Landsat 8 > products are > 12bit data, proper signature files cannot be produced by i.class. > > You could try rescaling data to 8bit and see if i.class and i.maxlik works. > > Best > > Venka > > P.S. I hope i.class will be support 12, 16bit images in future. > > > > On 2013/11/27 0:47, Cesar Augusto Ramírez Franco wrote: > > Hello everyone, > > 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. > > 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.maxlik group=lsat7_2000_RGB subgroup=lsat7_2000_RGB sigfile=clustlsat7 > class=lsat7_classes reject=lsat7_classes_rej > #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] > > 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? > > > > > _______________________________________________ > grass-user mailing > listgrass-user@lists.osgeo.orghttp://lists.osgeo.org/mailman/listinfo/grass-user > > > > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user > -- *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
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