[Gdal-dev] Reducing GeoTIFF color depth from 24 bit to 8 bit

[Rich Signell]

GDAL folk,

Is is possible to use GDAL to reduce the color depth of a GeoTIFF from
24 to 8 bit?

I've looked at doc and e-mail archives for 20 minutes and haven't
found it yet - hoping someone can spend 30 seconds on the answer!

My work around is to reduce the colordepth in Irfanview, but then I
need to add the georeferencing info back in again with gdal_translate.
 This works, but there must be an easier way.   This is all because
our ship's navigation software (HYPACK) doesn't seem to like 24 bit
GeoTIFF, but 8 bit is fine.

Thanks,
Rich

-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598