[Gdal-dev] RasterIO on bands with ColorTable

[Sheykhet, Rostic]

Frank,

The pyramid .ovr file contained 3-band raster data and I was reading
just the red band.  Sorry for the confusion.

Thanks a lot.

Rostic

-----Original Message-----
From: Frank Warmerdam [mailto:fwarmerdam at gmail.com] 
Sent: Wednesday, May 04, 2005 1:03 PM
To: Sheykhet, Rostic
Cc: gdal-dev at remotesensing.org
Subject: Re: [Gdal-dev] RasterIO on bands with ColorTable

On 5/4/05, Sheykhet, Rostic <rsheykhet at sanz.com> wrote:
> Hello,
> 
> I am trying to perform RasterIO on a band that references a color
table.
> When the source and destination image dimensions are different, I get 
> back a band that has indexes into blank/invalid color table entries.  
> I assume this is because of the decimation procedure.  Is there a way 
> to modify this behavior?

Rostic,

RasterIO() level resampling should all be "nearest neighbour", and so
not introduce any new values.   Is it possible you have built overviews
on the file in question with averaging?  Perhaps the format is a lossy
compression format? 

Best regards,
-- 
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