[gdal-dev] Reducing the size of a GeoTIFF file with significant blackfill

[Jukka Rahkonen]

Jan Hartmann <j.l.h.hartmann <at> uva.nl> writes:

> 
> 
>     Hi Peter,
>       You can get a compress-ratio to about 10% of the original size
>       with the GDAL option -co COMPRESS=JKEG -co PHOTOMETRIC=YCBCR.
>       Perhaps even more for you sort of data. Of course that compression
>       is lossy, so for archival purposes it is useless. For viewers, you
>       won't note the difference and it is quite fast, especially if you
>       use gdaladdo with the option --config COMPRESS_OVERVIEW JPEG
>       --config PHOTOMETRIC_OVERVIEW YCBCR

We can't forecast the speed without knowing which viewer is used. They do
not all include GDAL. GDAL based viewer should have been fast already with
the COMPRESS=DEFLATE image at least with close zoom. Pyramid layers or
reduced resolution layers or overviews or how one wants to call them are
very good to have but that also depends on the viewer.

-Jukka Rahkonen-