[gdal-dev] BigTIFF Overviews ( OVR files )

[David Fogel]

Hi Even:

The GeoTIFF file is described below (output from gdalinfo).  The
pre-compiled code is from Tamas' site:
http://vbkto.dyndns.org/sdk/
I am using the MSVC2008 version ( scroll to the bottom of the page ).
This ought to be v1.7.0 with some or all of the code for HFA files
folded into it.

The workstation is running Windows 7 64-bit w/ 8 GB of RAM and too
much disk space to know what to do with .. for the moment.

Thanks.
= David

----- % cut here % -----
Driver: GTiff/GeoTIFF
Files: Central_North.tif
Size is 119999, 74401
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (-31.999583000000001,60.000416333276846)
Pixel Size = (0.000833333333333,-0.000833333333333)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  ( -31.9995830,  60.0004163) ( 31d59'58.50"W, 60d 0'1.50"N)
Lower Left  ( -31.9995830,  -2.0004170) ( 31d59'58.50"W,  2d 0'1.50"S)
Upper Right (  67.9995837,  60.0004163) ( 67d59'58.50"E, 60d 0'1.50"N)
Lower Right (  67.9995837,  -2.0004170) ( 67d59'58.50"E,  2d 0'1.50"S)
Center      (  18.0000003,  28.9999997) ( 18d 0'0.00"E, 29d 0'0.00"N)
Band 1 Block=119999x1 Type=Int16, ColorInterp=Gray
  NoData Value=-32768
  Metadata:
    LAYER_TYPE=athematic
----- % cut here % -----

On Tue, Feb 9, 2010 at 2:09 PM, Even Rouault
<even.rouault at mines-paris.org> wrote:
> Could you append the output of gdalinfo on the TIF you make overviews on and
> the exact gdaladdo you're using (mainly if you use one particular resampling
> algorithm) ?
>
> Le Tuesday 09 February 2010 22:57:26 David Fogel, vous avez écrit :
>> Hi:
>>
>> In the process of moving data into GeoTIFF, I am re-creating pyramids
>> (OVR files).  The good news: It takes fewer than ten minutes to create
>> an LZW Horizontal Differenced compressed 3.5 GB file on a Windows 7
>> box using GDAL 1.70+ ( via Tamas Szekeres site; 64-bit precompiled ).
>>
>> The OVR files are problematic.  Using gdal_translate, I can resize by
>> 50% in less than ten minutes.  Using gdaladdo, the first layer ( "2" )
>> takes hours to complete.
>>
>> This is for SRTM 16-bit data.  It appears that something is amiss.
>>
>> Tips and tricks?
>>
>> Thanks!
>> = David
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>
>