As recommended by Paul Ramsey, tiled schema is a better option, so I add it
to gdal_translate command.

Thanks!


a. Reading ECW and compressing to JPG (set your favourite quality, 80 is a
good choice for orthoimages; also CACHEMAX could be increased):

gdal_translate --config GDAL_CACHEMAX 1000 --config GDAL_PAM_ENABLED NO -of
GTIFF -co COMPRESS=JPEG -co TILED=YES -co JPEG_QUALITY=80 -co
PHOTOMETRIC=YCBCR "source_image.ecw" "target_image.tif"

b. Adding internal pyramids/overviews with JPG compression (select your
resampling method, I prefer average):

gdaladdo --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW
YCBCR --config INTERLEAVE_OVERVIEW PIXEL -r average "image.tif" 2 4 8 16 32
64 128


2015-08-04 17:23 GMT+02:00 Steve Golden <[email protected]>:

> If you have access to Windows XP and can install GDAL, gdal_translate is
> the
> way to go to convert ECW to something else and GeoTIFF should be on your
> list for that something else.  There are a lot of webpages out there with
> sample gdal_translate commands, but I recommend reading about  GeoTIFF
> compression
> <
> http://blog.cleverelephant.ca/2015/02/geotiff-compression-for-dummies.html
> >
> from a very good source.
>
> -Steve
>
>
>
> --
> View this message in context:
> http://osgeo-org.1560.x6.nabble.com/How-to-convert-ECW-using-open-source-packages-into-something-else-tp5218390p5218484.html
> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
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