[Gdal-dev] Reading Erdas Imagine Files Through GDAL 1.3.2

[Frank Warmerdam]

Jingmu Yang wrote:
> I experience the performance downgrade after linking my application into GDAL
> 1.3.2 to read (open) large (200MB) Erdas Imagine files.  It paused about
> 20-30 seconds in calling GDALOpen.  But when I used the early GDAL release
> (1.2.6) reading such files were very fast.  What happens with the latest
> release of GDAL?

Jingma,

There have been a variety of improvements to the HFA driver in the last year
or two.  I suspect you are suffering from a lot of time being spent turning
a color table into a GDAL "Raster Attribute Table".  I recall having to
do some serious work to improve the performance of this, though I'm not
clear on whether that was before or after the GDAL 1.3.2 release. I'd
suggest trying your gdalinfo, and the gdalinfo from a recent FWTools and
see if the fwtools gdalinfo is nice and fast.  Alternatively, try building
from GDAL CVS source for comparison.

If the problem persists with recent source then please file a bug and make
your file available somewhere for me to try with.

Best regards,
-- 
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