Many thanks! This seems to be exactly what I was looking for! Definitely, the otb doc needs major improving. This is what is stated regarding these arguments: "Sub-Sampling Rate X: Generates a result at a coarser resolution with a given sub-sampling rate along X"
which is just a side effect, the main definition should be that the metric window is displaced at that rate. (If it were just a matter of a coarser result the process would not be so much faster). Nevertheless, I'd appreciate confirmation that this is really what happens. I feel uneasy conjecturing... Agus On Thu, Nov 27, 2014 at 1:15 PM, Carlos Hernando <[email protected]> wrote: > I think that if you uses the subsampling option you can perform consecutive > registrations of increasing accuracy with a smaller metric windows. in this > way, you can maybe obtain similar results reducing the time. > > > Best regards > Carlos > > El miércoles, 26 de noviembre de 2014 17:44:04 UTC+1, alobo escribió: >> >> After having used otbcli_FineRegistration quite a lot, >> I have come to the conclusion that the Metric window defined by Metric >> Radius X and >> Metric Radius Y must be quite large, otherwise the calculated offset >> values are prone >> to be too local (it is easy to find sporious high correlations at >> positions that are not geometrically correct if the window is over a >> homogeneous area) and unrealistically variable. >> >> The problem is that the program is very slow for large Metric windows. >> Neverthless, there is no reason why the metric window should be >> positioned at every pixel. >> FineRegistration could have "jumpX", jumpY" arguments so that the >> metric is calculated >> every jumpX and jumpY pixels, which would speed up computation a lot. >> For example >> >> -erx 5 -ery 5 -mrx 121 -mry 121 -jumpx 31 -jumpy 31 >> would be enough >> The final >> X and Y offset "images" would then be just interpolated. It is more >> important a large mrx and mry >> than having the values calculated at every pixel. >> >> This should not be hard to implement for someone knowing well the >> code. I would be willing to intensively test the new implementation. >> >> 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.
