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). > 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.) > 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. > #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? > 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 _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
