[Gdal-dev] caching of the blocks

Stephane Routelous route at cae.com
Fri Aug 27 13:58:06 EDT 2004

Hi Frank,

I've done a performance test for comparing RasterIO vs ReadBlock

I'm reading a big geotiff image (8100x7200)

the results are : RasterIO=8752ms ReadBlock=6776ms


-----Original Message-----
From: Frank Warmerdam [mailto:warmerdam at pobox.com]
Sent: Friday, August 27, 2004 1:39 PM
To: Stephane Routelous
Cc: 'gdal-dev at remotesensing.org'
Subject: Re: [Gdal-dev] caching of the blocks

Stephane Routelous wrote:
> Hi Frank,
> Thanks a lot for your quick answer.
> I need to use the ReadBlock to have the best performances, and also
> of the resampling.
> I will continue to use it and implement my own cache mecanism.


Note, you can call RasterIO() at 1:1 resolution on exact block boundaries
and you will have essentially the same performance but with GDAL block
caching kicking in.

Best regards,
I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

More information about the Gdal-dev mailing list