[Benchmarking] Geotiff and overviews

[Frank Warmerdam]

Anne-Sophie Collignon wrote:
> Hello,
> 
> If we cannot take advantage of the geotiff overviews, is that a problem
> for some of you, if we create external overviews and attach them to the
> original raster Geotiff service (the goal would be to reflect the same
> as with the internal overview, and the tool used would be documented,
> like for the shape index)? 

Anne-Sophie,

I don't see any problem with you creating your own format of overviews.

 > Or anyone knows how we could extract the
> internal overviews to have the capabilities to attach them to the
> service ?

I am familiar with the overview format, but not with what you can do
with your software.  You could use the GDAL "dumpoverviews" utility
to dump out the overviews as individual external geotiff files, but I don't
see much benefit in this over just creating your own.

It would of course be nice if Erdas support standard TIFF overviews. But
I presume that would require non-trivial engineering work.

Best regards,
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