Hi,
I made a trial with the biggest image I had on my computer and it was of size 288000 by 480000 pixels. Running gdaladdo as
gdaladdo -r average -ro --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR
–config BIGTIFF_OVERVIEW YES test.jp2 2 4 8 16 32 64 128 256
It took 22 hours to create the overviews. After 9 hours the progress bar showed 75% so process was slowing down till the end.
It is a long time but it could be tolerated.
Ammar has a four times bigger image but zero progress after four days means that it just does not work. I wonder if the original bigtiff is without tiles and gdaladdo has to read 700000 pixel wide rows. Anyway, perhaps that image begins to be unreasonably big.
Alternatives to gdaladdo is to create a layer group for Geoserver and try is downsampling the image with gdal_translate is successful. Use –outsize 50% 50% for doubling the pixel size. If nearest neighbour resampling is not good you may have a try with gdalwarp which gives more alternatives: near, bilinear, cubic, cubicspline, lanczos, average, and mode.
Also, once you have now a bigtiff without stripes and you do not want to do more experiments, you can split it back to smaller pieces which are easier to handle with gdal_translate by using -srcwin xoff yoff xsize ysize.
-Jukka Rahkonen-
···
Lähettäjä: Jonathan Moules [mailto:jonathanmoules@anonymised.com4942…]
Lähetetty: 21. tammikuuta 2014 14:23
Vastaanottaja: Ammar
Kopio: geoserver-users@lists.sourceforge.net
Aihe: Re: [Geoserver-users] White lines in merged GeoTIFF files after ImageMosaicing
Hi Ammar,
The problem with this approach is that I tried to create overviews for the image and it took 4 continuous days of gdaladdo running without any progress until I had to cancel the gdaladdo operation.
That’s a known “limitation” of Gdal. It can’t handle large files well when pyramiding/overviewing.
I’m afraid I’m not sure what the issue with the white lines is though. Maybe someone else does?
Jonathan
This transmission is intended for the named addressee(s) only and may contain sensitive or protectively marked material up to RESTRICTED and should be handled accordingly. Unless you are the named addressee (or authorised to receive it for the addressee) you may not copy or use it, or disclose it to anyone else. If you have received this transmission in error please notify the sender immediately. All email traffic sent to or from us, including without limitation all GCSX traffic, may be subject to recording and/or monitoring in accordance with relevant legislation.