Thanks Carlos, fully clarified now. I've checked and all values I find are always <=0. That note, "This class returns the negative mutual information value." should make it to the otb manual as well.
Agus On Mon, Sep 7, 2015 at 11:15 AM, Carlos Hernando <[email protected]> wrote: > 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]> 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]> 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] >> > 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. > > -- > -- > 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. -- -- 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.
