[gdal-dev] gdaladdo / BuildOverviews mismatch

[Ben Discoe]

I am trying to figure out exactly what options exist for overlays, and the documentation has some problems.

For the application gdaladdo, documented here:
http://www.gdal.org/gdaladdo.html

It says the resampling methods are "nearest, average, average_mp, average_magphase, mode", with "average_mp" and "mode" not to be used.

In the underlying function GDALDataset::BuildOverviews:
http://www.gdal.org/classGDALDataset.html

It says the resampling methods are "NEAREST", "AVERAGE" or "MODE".

It seems these are not in agreement.  In the source code itself (gdal 1.5.1, overview.cpp) there are mentions of:

	"NEAR*"
	"AVER*"
	"AVERAGE_MAGPHASE"
	"AVERAGE_BIT2*"
	"AVERAGE_BIT2GRAYSCALE"
	"AVERAGE_BIT2GRAYSCALE_MINISWHITE"
	"AVERAGE_MP"
	"NO_REGEN:"

It seems that both the developer and end-user documentation needs updating to reflect the actual options available.  E.g. adding and explaining the BIT2 options and removing MODE.  gdaladdo should also state what the default method is (i had to read the source code to find out it is "nearest".)

Do these sort of doc fixes need to be logged in Trac, or is there some other way they get done?

Thanks,
Ben