[Gdal-dev] ArcGrid to IMG conversion: huge file

[Thom DeCarlo]

COMPRESS doesn't seem to be very good. Try again with:

gdal_translate -co COMPRESS=LZW pop2000 pop2000.tif

And I also make my tiff file tiled for faster access, so I add "-co
TILED=YES"

--
Thom DeCarlo
-------------------------------------------------------
        Confidence is the feeling you get 
    before you fully understand the situation.

> -----Original Message-----
> From: Markus Neteler
> Sent: Friday, March 10, 2006 8:16 AM
> To: 'GDAL-dev list'
> Subject: Re: [Gdal-dev] ArcGrid to IMG conversion: huge file
> 
> So, here my report:
> 
>  gdal_translate -of HFA -co COMPRESSED=YES pop2000 pop2000.img
> 
>  du -h pop2000.*
>  3.5G    pop2000.ige
>  8.0K    pop2000.img
> 
>  gdal_translate -co COMPRESS=DEFLATE pop2000 pop2000.tif
>  du -h pop2000.*
>  92.0M    pop2000.tif
> 
> Clear decision :-)
> 
> Markus
> 
> On Thu, Mar 09, 2006 at 06:41:21PM +0100, Markus Neteler wrote:
> > Thanks, Frank and Thom,
> >
> >  I'll try.
> >
> > Markus
> >
> > On Thu, Mar 09, 2006 at 09:41:15AM -0500, Thom DeCarlo wrote:
> > > Markus,
> > > The IMG format doesn't support the concept of "NODATA", and by default
> does
> > > not use compression. It does support ESRI-style run length encoding,
> but I
> > > haven't seen it used much. You might do better converting to geotiff
> which
> > > supports LZW compression and Frank has extended it to support a NODATA
> tag.
> > >
> > > --
> > > Thom DeCarlo
> > > ------------------------------------------------------
> > >            Experience is a wonderful thing
> > > It allows you to recognize a mistake when you make it again.
> > >
> > > > -----Original Message-----
> > > > From: Markus Neteler
> > > > Sent: Thursday, March 09, 2006 6:04 AM
> > > > To: GDAL-dev list
> > > > Subject: [Gdal-dev] ArcGrid to IMG conversion: huge file
> > > >
> > > > Hi,
> > > >
> > > > when converting the
> > > >   Landscan Global Population 2000 Database
> > > > from
> > > >   http://www.fao.org/geonetwork/srv/en/metadata.show?id=1261
> > > >
> > > [snip]
> > > >
> > > > Apparently the NoData isn't passed to IMG.
> > > > Is the created IMG file probably uncompressed
> > > > which leads to this big file size?
> > > >
> > > > Best regards
> > > >
> > > >  Markus
> > > >
> > >
> > >
> > >
> >
> > --
> > Markus Neteler     <neteler itc it>       http://mpa.itc.it
> > ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
> > MPBA - Predictive Models for Biol. & Environ. Data Analysis
> > Via Sommarive, 18        -       38050 Povo (Trento), Italy
> 
> --
> Markus Neteler     <neteler itc it>       http://mpa.itc.it
> ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
> MPBA - Predictive Models for Biol. & Environ. Data Analysis
> Via Sommarive, 18        -       38050 Povo (Trento), Italy
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