Hi Guillaume,
Thanks for the tips on object-based classification. I am in the same position as Geoffrey and Patricia. I have been able to successfully segment an image. However I am really struggling with the classification part. On my most recent attempt after reading your suggestions I tried running OGRLayerClassifier. When I click Run, the window closes and nothing seems to have happened. I am probably missing something obvious. I’m not sure I understood your suggestion about ‘*Adding several numeric fields to store the features attached to geometries. **The fields can be extracted from a raster with LSMSVectorization and modified with QGis.’* Won’t the training layer just need to have a ClassID field added? The mean and variance of the bands are the only other required fields? Thanks. Best Regards, Mark Le mardi 3 janvier 2017 21:43:57 UTC+8, Guillaume Pasero a écrit : > > Hi, > > You should use Train*Vector*Classifier instead of TrainImagesClassifier. > This will train and produce a SVM model ("-io.out" output file). You will > have to set (at least) : > > - Input Vector Data (io.vd) > - Output model (io.out) > - Field names for training features (feat) > - Field containing the class id for supervision (cfield, in your case > it will be "training") > - Classifier to use for the training (classifier = libsvm) > > However, before using this application, you will have to prepare a vector > dataset with only your training polygons (polygons with a missing value in > the field "training" will make the application crash). > > Once you have the output model file (simple text/xml file) you can use it > to do the classification on the full dataset (using application > OGRLayerClassification). > > Regards, > Guillaume > > On 01/02/2017 11:54 PM, Geoffrey Balme wrote: > > I forgot to say that after the segmentation, I added a field in my vector > attribute table named "training", and I gave some numeric values to few > polygons based on the classes I want the segments to be classified in (3 > classes) > > So now I'm with a few polygons having a training value, and most of the > polygon having no training value, and I want to do the svm classification > from this. > > Le lundi 2 janvier 2017 23:52:47 UTC+1, Geoffrey Balme a écrit : >> >> Hi Guillaume, >> >> I'm also trying to do supervised object-based classification. >> What I did so far is a meanshift segmentation on my satellite raster >> image. >> Then I did TrainImagesClassifier (svm) on the vector results of the >> segmentation. >> And at this point I'm not sure anymore what to do as there was no output >> on the previous step. >> Could you guide me from the segmentation to have an object-based >> classification using SVM ? >> >> (I tried to do OGRLayerClassification, but had no idea of what to put in >> the xml inputs etc..., the only input I have are my raster and my >> segmentation vector result) >> >> Thank you ! >> >> Le jeudi 24 novembre 2016 14:46:00 UTC+1, Guillaume Pasero a écrit : >>> >>> Hi Patricia, >>> >>> If I understand right, you want to perform object-based classification. >>> >>> In OTB-5.6.1 there is the application TrainVectorClassifier to train a >>> classifier based on input geometries. You have to set several fields in the >>> geometries you want to use for training : >>> >>> - one field to indicate the class of the geometry >>> >>> - several numeric fields to store the features attached to geometries. >>> >>> The fields can be extracted from a raster with LSMSVectorization and >>> modified with QGis. >>> >>> After the training, you can either apply the model on the full set of >>> geometries (with OGRLayerClassifier), or try to apply it on a raster (with >>> ImageClassifier, but more difficult). >>> >>> Regards, >>> >>> Guillaume >>> On 11/24/2016 02:09 PM, Patricia Lourenco wrote: >>> >>> Dear all, >>> I am new with OTB-Monteverdi 5-6-1. >>> >>> I want to classify an image based on the segments created in the >>> LSMVSVectorization (step 4 of the segmentation)using OTB/Monteverdi >>> versions 5.6.1. >>> However, I am not being able to do it. >>> >>> My questions are: >>> >>> 1. Which are the steps that I should take to do a classification based >>> on segmentation? >>> >>> 2. Which OTB-Application should I use to select the segments for my >>> classes? >>> >>> Thank you, in advance, for your help. >>> >>> Sincerely, >>> Patricia >>> -- >>> -- >>> Check the OTB FAQ at >>> http://www.orfeo-toolbox.org/FAQ.html >>> >>> You received this message because you are subscribed to the Google >>> Groups "otb-users" group. >>> To post to this group, send email to otb-...@googlegroups.com >>> To unsubscribe from this group, send email to >>> otb-users+...@googlegroups.com >>> For more options, visit this group at >>> http://groups.google.com/group/otb-users?hl=en >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "otb-users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to otb-users+...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> -- >>> <http://www.c-s.fr> *Guillaume PASERO* >>> Responsable technique >>> *Business Unit E-SPACE & Geo Information - Département Image & >>> Applications* >>> >>> *CS Systèmes d'Information* >>> Parc de la Grande Plaine - 5, Rue Brindejonc des Moulinais - BP 15872 >>> 31506 Toulouse Cedex 05 - FRANCE >>> +33 561 17 64 21 - guillaum...@c-s.fr >>> >> -- > -- > Check the OTB FAQ at > http://www.orfeo-toolbox.org/FAQ.html > > You received this message because you are subscribed to the Google > Groups "otb-users" group. > To post to this group, send email to otb-...@googlegroups.com > <javascript:> > To unsubscribe from this group, send email to > otb-users+...@googlegroups.com <javascript:> > For more options, visit this group at > http://groups.google.com/group/otb-users?hl=en > --- > You received this message because you are subscribed to the Google Groups > "otb-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to otb-users+...@googlegroups.com <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- > <http://www.c-s.fr> *Guillaume PASERO* > Responsable technique > *Business Unit ESPACE & GeoInformation - Département Payload Data & > Applications* > > *CS Systèmes d'Information* > Parc de la Grande Plaine - 5, Rue Brindejonc des Moulinais - BP 15872 > 31506 Toulouse Cedex 05 - FRANCE > +33 561 17 64 21 - guillaum...@c-s.fr <javascript:> > -- -- Check the OTB FAQ at http://www.orfeo-toolbox.org/FAQ.html You received this message because you are subscribed to the Google Groups "otb-users" group. 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