saygin <[email protected]> wrote: > > Hello, > > I am trying to train my .tif image with approximately 1500 pixels. I have 4 > classes and one of them has the lowest training with 115 pixels. If I chose > training and validation sample ratio 0.5, and using SVM OpenCV RBF with > parameter > optimization I get 232 training and 184 validation at log file. I am not very > familiar with OTB and want to ask does not it use approximately half of all > training pixels? >
No. It will set the number of samples per class to the number of samples of the class which has the fewer samples. In your case 115. If you have 4 classes, you get: 115 * 0.5 * 4 = 230 Then, why the number of training samples is not equal to the number of validation? I think it is because first the samples are selected, and then they are randomly split between training and validation, and this may introduce some variation accros classes. The current choices for the sampling procedure need improvement and some thinking about this is ongoing (http://wiki.orfeo-toolbox.org/index.php/Refactoring_of_the_classification_chain). Do not hesitate to give you 2 cents about it. Jordi -- -- 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 [email protected] To unsubscribe from this group, send email to [email protected] 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 [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
