[Gvsig_english] Problem loading big raster file.

[Rahkonen Jukka]

Hi,

This is (only) partly true. Tiff is the fastest fileformat for, let's say, Mapserver, which is also reading those through gdal. You could try what happens if you use the standard Mapserver recipe for tiff files:
make it tiled with 

  gdal_translate -of GTiff -co TILED=YES -co TFW=YES original.tif tiled.tif

and next add the overviews:

  gdaladdo -r average tiled.tif 2 4 8 16 32 64

ECW is not at all a bad alternative, though.

-Jukka Rahkonen- 

> -----Alkuperäinen viesti-----
> Lähettäjä: gvsig_internacional-bounces at listserv.gva.es 
> [mailto:gvsig_internacional-bounces at listserv.gva.es] Puolesta 
> Luis W. Sevilla
> Lähetetty: 2. maaliskuuta 2010 17:21
> Vastaanottaja: Users and Developers mailing list
> Aihe: Re: [Gvsig_english] Problem loading big raster file.
> 
> Hi,
> IMHO you're getting the expected behavior. As plain tiff is not a 
> pyramid/tiled file format, gdal raster driver must parse almost the 
> whole file, and even more, it must read *complete* all lines it's 
> rendering, even if you're only seing 200 px wide, it needs to 
> read the 
> whole 10001.
> You may try to convert the file into an ECW (that it's a pyramid and 
> tiled format), and you'll see a boost in performance, at 
> least 10 times 
> faster.
> 
> hope it helps
>     Luis
> 
> Wolfgang Qual wrote:
> > Dear Manuel, Luis, list,
> > the file is a tiff-file. See gdalinfo-output
> >
> > wolfgang.qual at rgu04-200:~$ gdalinfo 44655342.tif
> > Driver: GTiff/GeoTIFF
> > Files: 44655342.tif
> > Size is 10001, 10001
> > Coordinate System is:
> > PROJCS[" Projection Name = Transverse Mercator Units = 
> meters GeoTIFF Units
> > = meters",
> >     GEOGCS[" Unable to match Ellipsoid (Datum) to a 
> GeographicTypeGeoKey
> > value Ellipsoid = Bessel Datum = DE_DHDN (",
> >         DATUM["unknown",
> >             SPHEROID["unnamed",6377397.155,299.1528131060796]],
> >         PRIMEM["Greenwich",0],
> >         UNIT["degree",0.0174532925199433]],
> >     PROJECTION["Transverse_Mercator"],
> >     PARAMETER["latitude_of_origin",0],
> >     PARAMETER["central_meridian",12],
> >     PARAMETER["scale_factor",1],
> >     PARAMETER["false_easting",4500000],
> >     PARAMETER["false_northing",0],
> >     UNIT["metre",1,
> >         AUTHORITY["EPSG","9001"]]]
> > Origin = (4464999.950000000186265,5343000.049999999813735)
> > Pixel Size = (0.100000000000000,-0.100000000000000)
> > Metadata:
> >   AREA_OR_POINT=Area
> >   TIFFTAG_SOFTWARE=IMAGINE TIFF Support
> > Copyright 1991 - 1999 by ERDAS, Inc. All Rights Reserved
> > @(#)$RCSfile: etif.c $ $Revision: 1.10.1.9.1.9.2.11 $ 
> $Date: 2004/09/15
> > 18:42:01EDT $
> >   TIFFTAG_XRESOLUTION=1
> >   TIFFTAG_YRESOLUTION=1
> >   TIFFTAG_RESOLUTIONUNIT=1 (unitless)
> > Image Structure Metadata:
> >   INTERLEAVE=PIXEL
> > Corner Coordinates:
> > Upper Left  ( 4464999.950, 5343000.050) ( 11d31'43.97"E, 
> 48d13'29.74"N)
> > Lower Left  ( 4464999.950, 5341999.950) ( 11d31'44.27"E, 
> 48d12'57.36"N)
> > Upper Right ( 4466000.050, 5343000.050) ( 11d32'32.43"E, 
> 48d13'29.94"N)
> > Lower Right ( 4466000.050, 5341999.950) ( 11d32'32.72"E, 
> 48d12'57.56"N)
> > Center      ( 4465500.000, 5342500.000) ( 11d32'8.35"E, 
> 48d13'13.65"N)
> > Band 1 Block=10001x1 Type=Byte, ColorInterp=Red
> > Band 2 Block=10001x1 Type=Byte, ColorInterp=Green
> > Band 3 Block=10001x1 Type=Byte, ColorInterp=Blue
> >
> > Other files worked better, e.g. a larger ERDAS-rasterfile 
> with internal
> > overviews.
> >
> > Best,
> > Wolfgang
> >
> >   
> 
> 
> -- 
> Director Técnico / CTO
> Sigrid - Grupo Acotelsa
> Tel. +34 600 433 808
> http://www.stereowebmap.com
> http://www.sigrid.es 
> 
> The secret to programming is not intelligence, though of 
> course that helps. It is not hard work or experience, though 
> they help, too. The secret to programming is having smart 
> friends. (Ron Avitzur)
> 
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