Hi,
With gdal utility programs:
1) gdalinfo your_image.tif
This tells if you have tiles and overviews and some more useful information.
2) gdal_translate -of GTiff -co TILED=YES your_image.tif tiled_image.tif
This makes a new, tiled tiff with default tile size of 256 by 256 pixels.
3) gdaladdo -r average -ro tiled_image.tif 2 4 8 16 32 64 128 256
This creates an external overview file which contains set of generalised versions of the input file with pixel sizes of 2, 4, 8, ...256 times the original one. Size of this overview file will be about 30% of the original. External overviews mean that the original image file remains the same and overviews are stored into an additional file with .ovr name extension. It is also possible to add the overviews inside the original tiff also but I prefer using external file. Then there will be less bytes to save when image goes to an archive.
Syntax of commands may not be totally correct but you want for sure read the usage instructions from www.gdal.org any way.
-Jukka Rahkonen-
Post by Imran RajjadHi,
well you I have neither internal tiling nor overviews? how do I do that , do
I need to make tiles through geowebcache? I tried doing that but it was
taking a of time, in fact the estimated time against the threads was in days
when i asked it to make tiles with 7 threads! or is there any file format
that you recommend other than ECW
Post by Imran Rajjadregards,
Imran
Post by Imran RajjadHi list,
I just uploaded a geoTiff of size 1.01 Gb, now the problem is that GS
response has slowed down and at times the image is not displayed at a random
scale, the file has been uploaded with default settings, any idea what I
might be doing wrong here,Im calling the image through WMS service through
URL which has other layers in it aswell
A 1GB GeoTiff file needs to be processed to get good performance, in
particular it needs to have both internal tiling and overviews.
If you don't have both of them accessing it might be very slow
Cheers
Andrea
--
I.R