Cesar Augusto Ramírez Franco wrote: > > > 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.
Nikos Alexandris: > > 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 ok > > > 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) Right, I didn't pay much attention. Apologies. > > 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. Same error (of mine) as above, you correctly used a group with three bands. > The supervised classification does work, i.cluster generates a signature > file and i.maxlik success to create the classes raster map You mean the _un_supervised I guess. > > #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 Sorry for my typo -- I meant to write "only with 1 class?", "can you try with more than 1 class, i.e. 3 or 4 classes?". > I'm doing some tests creating a test vector with my classes as areas, how many classes? > then converting it to raster with v.to.rast, can you post the exact command? What values are you attributing to the rasterised classes? > 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 I don't think it is broken as it usually works/ed fine. But we'll try to nail that down. Nikos _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
