[gdal-dev] Overviews with a factor of 4

[Andrew C Aitchison]

I am writing a driver that reads files that have overviews with linear 
scale factors 4, 16, 64 rather than the 2, 4, 8, 16, 32, 64, ...
supported by GDALRasterBand::GetOverview().

Is there a way to let the library know that some overviews are not available,
or code I could use to scale (shrink) the data read rather than reimplementing
the wheel ?

-- 
Andrew C. Aitchison					Cambridge, UK
 			andrew at aitchison.me.uk