I think that it uses the Mattes version of MI, which provides negative values as output: http://www.itk.org/Doxygen/html/classitk_1_1MattesMutualInformationImageToImageMetric.html
Best regards Carlos El viernes, 4 de septiembre de 2015, 17:38:17 (UTC+2), alobo escribió: > > No, they are not. Could the metric be centered around the mean? > Somebody with enough knowledge could check the code? Should I fill a > bug report? > Agus > > On Fri, Sep 4, 2015 at 4:57 PM, Jordi Inglada <[email protected] > <javascript:>> wrote: > > Hi Agus, > > > > Maybe a silly question: are these negative values large? > > > > This could be due to numerical precision errors in the estimation, since > > the entropy itself is estimated using histograms. > > > > Jordi > > > > Agustin Lobo <[email protected] <javascript:>> wrote: > >> > >> otbcli_FineRegistration using MI as metric produces negative values > >> (saved to the 3rd layer of the result of otbcli_FineRegistration). > >> > >> For example, in > >> otbcli_FineRegistration -ref StereoFixed.png -sec StereoMoving.png > >> -out FineRegistrationMI.tif -erx 2 -ery 2 -mrx 3 -mry 3 -m MI > >> > >> The 3rd "band" of FineRegistrationMI.tif has negative values. > >> > >> As > >> H(A+B) <=H(A)+H(B) > >> and > >> MI = H(A)+H(B)-H(A+B) > >> > >> MI cannot be <0 > >> > >> Any idea of what happens here? > >> > >> Thanks > >> > >> Agus > >> > >> -- > > > > -- > > -- > > 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] > <javascript:> > > To unsubscribe from this group, send email to > > [email protected] <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 [email protected] <javascript:>. > > For more options, visit https://groups.google.com/d/optout. > -- -- 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/d/optout.
