Actually, I do not quite understand: Is mfilter stating whether homologous points are filtered according to the value of "precision"? What do you mean by " padded according to the user defined *precision*.? What is threshold? Is it a radiometric distance or an spatial distance? I have tested and by increasing threshold I get more homologous points but also more of them get discarded (all other parameters equal):
$ otbcli_HomologousPointsExtraction -in1 IMG_0062.tif -band1 2 -in2 IMG_0062.tif -band2 1 -mode full -precision 50 -mfilter 1 -algorithm surf -out IMG_0062homSURF2.txt -threshold 0.6 2015 Aug 31 13:58:34 : Application.logger (INFO) Elevation management: setting default height above ellipsoid to 0 meters 2015 Aug 31 13:58:34 : Application.logger (INFO) Doing update 2015 Aug 31 13:58:40 : Application.logger (INFO) Found 15650 surf points in image 1. 2015 Aug 31 13:58:47 : Application.logger (INFO) Found 15722 surf points in image 2. 2015 Aug 31 13:59:14 : Application.logger (INFO) Found 740 homologous points. 2015 Aug 31 13:59:14 : Application.logger (INFO) 0 points discarded $ otbcli_HomologousPointsExtraction -in1 IMG_0062.tif -band1 2 -in2 IMG_0062.tif -band2 1 -mode full -precision 50 -mfilter 1 -algorithm surf -out IMG_0062homSURF2.txt -threshold 10 2015 Aug 31 13:59:26 : Application.logger (INFO) Elevation management: setting default height above ellipsoid to 0 meters 2015 Aug 31 13:59:26 : Application.logger (INFO) Doing update 2015 Aug 31 13:59:32 : Application.logger (INFO) Found 15650 surf points in image 1. 2015 Aug 31 13:59:38 : Application.logger (INFO) Found 15722 surf points in image 2. 2015 Aug 31 14:00:07 : Application.logger (INFO) Found 15650 homologous points. 2015 Aug 31 14:00:08 : Application.logger (INFO) 11469 points discarded Thanks! Agus On Wed, Jun 10, 2015 at 2:52 PM, Julien Michel <[email protected]> wrote: > Hi Agus, > > The readthedoc documentation export is experimental (Rashad did this a > while ago), and surely has some unsolved issues for now. If you refer to > the official documentation here : > > https://www.orfeo-toolbox.org/CookBook/CookBooksu103.html#x136-6690005.6.7 > > You will see that the table is right. For instance : > > precision > Float > > Estimated precision of the colocalisation function (in pixels). > > mfilter > Boolean > > Filter points according to geographical or sensor based colocalisation > > Regarding the precision parameter documentation, it is used at several > steps of the algorithm, as described in the Detailed Description of the > application : > > "In this mode, the corresponding spatial bin in the second image is > estimated using geographical transform or sensor modelling, and is padded > according to the user defined *precision*." > > "Last, in both modes the application can filter matches whose > colocalisation in first image exceed this *precision*." > > But we can update the documentation of the parameter if you think this is > not clear enough. > > Regards, > > Julien > > > Le 10/06/2015 10:00, Agustin Lobo a écrit : > > Doc on Homologous Point > Extractionhttp://otbcb.readthedocs.org/en/latest/Applications/app_HomologousPointsExtraction.html > > is incomplete. > For example, the only information provided on argument mfilter > is that it is a Boolean. No definition, no default value, no example. > > Instead, the command line help page is more informative: > "-mfilter <boolean> Filter points according to > geographical or sensor based colocalisation (optional, off by > default)" > > although it is not clear if the user has to write "on" or "1" to turn > it on. And it is not clear either what kind of filter (mean filter?) > and which radius > > Regarding "precision", there is also no definition in the table (the > information on > Parameter Type is just repeated) but it is later defined as in the > command line help page: > > "Estimated precision of the colocalisation function (in pixels). > Estimated precision of the colocalisation function in pixels." > > I do not say this definition is wrong, but it is no appropriate. The > definition must > state the role of the argument in the process. In this case, I > understand that the > algorithm searches, for a given point image in1 band1, an homologous point on > image in2 band2 within a radius equal to the value of precision in pixels. > Correct? > > Also, what happens if the user sets precision to i.e. 10 and mfilter is off? > > Thanks > > Agus > > > > > -- > Julien MICHEL > CNES - DCT/SI/AP - BPI 1219 > 18, avenue Edouard Belin > 31401 Toulouse Cedex 09 - France > Tel: +33 561 282 894 - Fax: +33 561 283 109 > > -- > -- > 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. 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