Le vendredi 05 octobre 2012 22:55:34, Frank Warmerdam a écrit : > On Fri, Oct 5, 2012 at 12:56 PM, Even Rouault > > <[email protected]>wrote: > > > >> 3) why is AVERAGE_MP considered unfit for use in the gdaladdo docs? > > > >> and why is it still available? > > > > > > > > Historical remain ? Could likely be undocumented. > > > > > > ok I will remove it, should it be removed/commented from the code also? > > > > Undocumenting seems appropriate. As far as removing the implementation, > > you might want to check with the original committer (FrankW) > > Etienne, > > Are AVERAGE_MP and AVERAGE_MAGPHASE really different things? That seems > odd.
Good question : svn blame points to activity dating back to 11 years ago ;-) AVERAGE_MP was added in http://trac.osgeo.org/gdal/changeset/1989 AVERAGE_MAGPHASE was added in http://trac.osgeo.org/gdal/changeset/2327 My undertanding of the code is that AVERAGE_MP, at the end of a regular AVERAGE, calls GDALOverviewMagnitudeCorrection() which does /* Correct the mean and standard deviation of the overviews of */ /* the given band to match the base layer approximately. */ and can apparently deal with regular or complex data types. GDALOverviewMagnitudeCorrection() compute statistics globally on the source band and on the overview band Whereas AVERAGE_MAGPHASE only works for complex data types, and does the correction only on the source window used to compute each target overview pixel. > > I don't know why it reports them as not ready for production use. That mention (specific to average_mp, but not to average_magphase) is in the initial documentation of gdaladdo : http://trac.osgeo.org/gdal/changeset/7276 Perhaps AVERAGE_MAGPHASE was assumed to be better than the original AVERAGE_MP ? > I would > not want them removed, but I don't mind them not being documented. > > I peeked at the qgis bug report about magphase but I see the test data is > no longer available. If there are problems with magphase support that can > be demonstrated and filed as a bug I'd be interested in resolving them. > > Best regards, _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
