[Geotiff] data types in bands

[Kyle Shannon]

Thanks Frank,
We are changing our input file type from a proprietary type to a well
supported/maintained data type.  GeoTiffs seemed the obvious choice.  Our
files can have 3, 5, 6, or 8 bands.  Is there a way to specify a band is
empty? We would like to keep the number of bands constant to allow user
defined bands (bands 9 - n).  We were going to user a GDT_Byte for those
bands to identify them as 'NoData'.  Is there a way to identify 'empty'
bands in a geotiff, or is it even worth it to try?


#===================================
Kyle Shannon | 5775 Highway 10 W.
Physical Science Technician | Missoula, MT 59808
RMRS Fire Sciences Lab | (406)829-6954
Fire, Fuels & Smoke - RWU 4405 |
work:kshannon at fs.fed.us<work%3Akshannon at fs.fed.us>
ksshannon at gmail.com |
#===================================


On Mon, Jun 22, 2009 at 3:50 PM, Frank Warmerdam <warmerdam at pobox.com>wrote:

> Kyle Shannon wrote:
>
>> I just have a quick question about geotiffs that I couldn't find in the
>> spec.  I am assuming that geotiffs do not support different data types for
>> single bands within that file.  Is that correct?
>>
>
> Kyle,
>
> This is a TIFF rather than GeoTIFF issue. The TIFF BitsPerSample
> tag has a value for each sample, so it is theoretically possible to
> have different bitspersample values for different band data types.
> However, this is not a baseline tiff, and would not be supported
> by very many software packages in the world.  So I'd strongly
> advise against doing this in most circumstances.
>
> 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<http://pobox.com/%7Ewarmerdam>
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>
>
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